Transport Secretary Chris Grayling said during the incident that he was in contact with the airport about the drone sighting, and had spoken to the home secretary and defence secretary.
BBC cameraman Martin Roberts, who works with drones, said he was driving on the M25 past Heathrow airport at about 17:45 GMT when he saw what he believes was a drone.
"I could see, I'd say around 300 feet up, very bright, stationary flashing red and green lights, over the Harmondsworth area," he said.
"I could tell it was a drone - these things have got quite distinctive lights - not a helicopter."
Gatwick said last week that it had spent £5m to prevent future attacks. Heathrow also confirmed it would be buying systems to guard against drones.
And it was announced this week that police would be given new powers to tackle the illegal use of drones.
In light of the Heathrow incident, British Airline Pilots' Association general secretary Brian Strutton called on ministers to further strengthen drone legislation and to ensure airports invested in protection technology.
"It's time to act swiftly and decisively," he added.
Speaking to ITV, Cabinet Office minister David Lidington said: "Clearly, the government is looking at the law to see whether there are ways in which it could be strengthened."
He added that airports also needed to "step up" investment in technology to detect and stop drones from flying.
BBC transport correspondent Tom Burridge said while the "significant" incident did not cause the same disruption as at Gatwick, it raised the question of how UK airports can deal with drones.
While they are looking at the latest technology, it is clear they are "playing catch-up" he said - adding that the aviation industry had been calling for "drastic action on this for months".
Alice Evans, BBC London, at Heathrow
A couple of hours after the first reports of a drone in the skies above Heathrow, it was business as usual in the Terminal 5 departure lounge - in a low blow to Gatwick, one member of staff told me it's because "we're a good airport".
Although flights were up and running again pretty quickly, there are still plenty of passengers who have faced disruption.
One of those is Catriona Walsh, who was on a flight from Basel.
Ms Walsh, who was doing a couple of days of work despite being on maternity leave, said her flight was held on the runway for about 50 minutes as staff told passengers about the drone.
"It was all calm - frustrating rather than worrying," she said.
Michael, a fellow passenger on the flight who did not want to provide his surname, was less optimistic.
"I was worried I might have to camp here," he said.
He said the problems here and at Gatwick have shown "exactly how to shut a country - this country - down", adding that police need to "just shoot drones down" as soon as they are sighted.
More than 140,000 passengers at Gatwick were affected during 36 hours of chaos between 19 and 21 December.
About 1,000 flights were cancelled there over three days due to the drone sightings.
A 14-year-old boy has been stabbed to death by attackers who knocked him off a moped, in what police believe was a targeted attack.
The boy, named locally as Jayden Moody, was found in Bickley Road, Leyton, in Waltham Forest, at 18:30 GMT on Monday.
Detectives believe the moped had been involved in a crash with a car, after which three men got out the vehicle, stabbed the teenager and drove off.
He died at the scene. No arrests have been made and a cordon is in place.
Jayden is believed to be the youngest victim to die on London's streets in the past year. There were 132 homicides in 2018, the highest total since 2008.
Det Ch Insp Larry Smith, of the Metropolitan Police, said: "Everything that we have learned about this attack so far indicates it was targeted and intent on lethal force from the outset.
"We are doing everything we can to catch those who carried out this cowardly attack and bring them to justice."
A section 60 order has been put in place, allowing officers to search anyone in the vicinity of the scene for weapons.
London's victims
Motives and circumstances behind killings varied - as did the age and gender of the victims.
Met commissioner Cressida Dick told Radio 4's Today Programme on 27 December that knife crime in London had "levelled off", praising the "Herculean effort" of officers.
London mayor Sadiq Khan, who said he was "greatly saddened" by the latest death, also set up the Violence Reduction Unit with £500,000 of funding in September to "treat violence like a disease".
Stella Creasy, the MP for Walthamstow, said she was "devastated" by the news from her constituency, describing it as a "terrible, horrific event".
Waltham Forest Council leader, Clare Coghill, called for those with information to come forward, warning that "to stay silent is to support murderers".
The Waltham Forest borough has had problems with gang crime and the local authority has spent £3 million on a four-year prevention programme.
It commissioned a report, published last summer, which found that so-called county lines drug gangs - which often target children and vulnerable youngsters - were operating in the area.
Ali Yamah, a tyre fitter who has worked opposite Bickley Road for 17 years, said the area could be intimidating at night.
"In my experience here there is drug dealing, this is the main source," the 48-year-old said.
"In the evening, now it's winter time, they put on masks.
"Sometimes we are afraid, people are afraid of this kind of behaviour."
London's blue-chip bourse .FTSE was up 0.9 percent at 0945 GMT after hitting its highest since Dec. 6 and the mid-cap index .FTMC was up 1.2 percent at its loftiest since Dec. 5.
European and Asian markets rallied after talks in Beijing with U.S. officials concluded earlier on Wednesday as the world’s two largest economies tried to seek a truce in their longstanding row.
A U.S. trade delegation member said “it’s been a good one for us” and the Chinese foreign ministry said results of the negotiations will be released later.
At home though, uncertainty over the United Kingdom’s divorce from the European Union deepened ahead of next week’s vote on the draft deal in parliament.
Prime Minister Theresa May’s government cautioned MPs on Wednesday that it was a delusion to think the government would be able to negotiate a new divorce deal with the European Union if parliament voted down her deal.
Her government suffered a defeat in parliament on Tuesday night when MPs who oppose leaving without a deal won a vote on creating a new obstacle to a no-deal Brexit.
Still, house-builders, one of the most battered sectors amid concerns about the slowing economy due to Brexit - led the gains on Wednesday after Taylor Wimpey (TW.L) maintained its 2018 results forecast and predicted solid 2019 sales.
Its shares advanced 5.3 percent, topping the blue-chip leader board and on track for their best day since July 2016, taking peers Persimmon (PSN.L) and Barratt (BDEV.L) with them.
“The glass half full interpretation of some of these trading updates from domestically focussed UK businesses indicates that investors are becoming a little less worried about problematic Brexit outcomes,” said Chris Bailey, Raymond James analyst.
Sainsbury’s (SBRY.L) shares slipped almost 3 percent in early deals on a worse-than-expected fall in underlying sales in the key Christmas quarter. By 0949 GMT, they erased losses to be 1.4 percent higher in choppy trading.
The update comes just a day after peer Morrisons (MRW.L) also missed sales forecast for the key period, while Tesco bucked the trend and led a rally after industry data covering the Christmas quarter sales.
Among mid-caps, IT infrastructure and service provider Softcat (SCTS.L) surged nearly 20 percent after an unscheduled trading update to its best day on record if gains hold.
Fashion retailer Ted Baker (TED.L) followed with a 11.2 percent jump on higher retail sales in the holiday period, tracking its biggest intraday gain in over two and half years.
Hargreaves Lansdown analyst Laith Khalaf said the update also helped allay concerns that news around CEO Ray Kelvin’s alleged conduct could have impacted trading in the all-important Christmas period.
AIM-listed Faroe Petroleum added 4.2 percent to match a 160-pence-per-share sweetened takeover bid from Norwegian oil firm DNO ASA, while mid-cap baker Greggs (GRG.L) rose 5.1 percent after it flagged a “very strong” finish to the year.
Political reporter(wp/reuters)::: British Prime Minister Theresa May failed to win over the Northern Irish party which props up her government to her Brexit deal on Wednesday, just hours before members of parliament were due to resume a debate on the divorce accord. The future of Brexit remains deeply uncertain - with options ranging from a disorderly exit from the European Union to another membership referendum - because British lawmakers are expected on Jan. 15 to vote down the deal May struck with the EU in November.
May pulled a vote on the deal last month, admitting it would be defeated, and promised to seek “legal and political assurances” from the EU.
But the Northern Irish Democratic Unionist Party (DUP) said it would not support the deal unless May dropped a part known as the backstop which is aimed at preventing a hard border between the British province and EU-member Ireland if both sides fail to clinch a future trade deal.
“The only thing which could swing the DUP round is if the backstop as it applies to the United Kingdom as a whole or to Northern Ireland specifically were removed from this agreement,” said Sammy Wilson, the DUP’s Brexit spokesman.
Wilson, who is among 10 DUP MPs propping up May’s minority government, cast as “window dressing” her proposals to give the Northern Irish assembly the power to vote against new EU rules if the border backstop comes into force after Brexit.
Her deal, he said, was “ruinous”. Britain is due to leave the EU on March 29 at 2300 GMT.
May has repeatedly ruled out delaying Brexit, though she has also warned British lawmakers that if they reject her deal then Brexit could be derailed or the United Kingdom could leave without a deal.
The government needs 318 votes to get a deal through parliament as seven Sinn Fein MPs do not sit, four speakers and deputy speaker do not vote and the four tellers are not counted.
BREXIT FANTASY?
May’s de-facto deputy cautioned MPs that it was a delusion to think the government would be able to negotiate a new divorce deal with the EU if parliament voted down her deal.
“I don’t think the British public are served by fantasies about magical, alternative deals that are somehow going to spring out of a cupboard in Brussels,” Cabinet Office Minister David Lidington said in an interview with BBC radio.
May’s government suffered a defeat in parliament on Tuesday when MPs who oppose leaving without a deal won a vote on creating a new obstacle to a no-deal Brexit.
The 303 to 296 defeat means the government needs explicit parliamentary approval to leave the EU without a deal before it can use certain powers relating to taxation law. May’s office had earlier played down the technical impact of defeat.
The defeat highlights May’s weak position as leader of a minority government, a split party and a deeply divided country as the United Kingdom prepares to leave the club it joined in 1973.
Lidington said the vote showed that many MPs do not want a no deal but he cautioned that it was not enough to show simply what MPs did not want. Without an alternative, he said, the default position would be leaving without a deal.
Some investors and major banks believe May’s deal will be defeated on Tuesday but that eventually it will be approved.
The ultimate Brexit outcome will shape Britain’s $2.8 trillion economy, have far-reaching consequences for the unity of the United Kingdom and determine whether London can keep its place as one of the top two global financial centres.
