London Bridge incident is potential act of terrorism: UK PM Theresa May

London: British Prime Minister Theresa May says an incident involving a vehicle and reported stabbings in London "is being treated as a potential act of terrorism."

May says it is a "fast-moving investigation" and her thoughts are with those caught up in the "dreadful events."

Police say a vehicle reportedly ran down pedestrians on London Bridge, and there were resports of stabbings nearby. They have also responded to an incident in another area of London, Vauxhaul.

Read: 20 people hurt in London attacks rushed to hospital

The BBC says more than one person has been killed. Jeremy Corbyn, the head of the Labour Party, said on Twitter: "Brutal and shocking incidents reported in London. My thoughts are with the victims and their families. Thank you to the emergency services."

Downing Street says Prime Minister Theresa May will chair a meeting of the government's emergency response committee on Sunday. A spokesman for May says the prime minister is in contact with officials and is being regularly updated.

May has not commented yet but in the past she has convened her emergency security Cabinet known as Cobra after major incidents. Britain's official terror threat had recently been lowered from "critical" after a bombing killed 22 people at an Ariana Grande concert in Manchester.

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London police say they are responding to reports that a vehicle hit pedestrians on London Bridge and that there were stabbings at busy Borough Market nearby. Soon after they responded to another incident in the Vauxhall area, over a mile away.

The Metropolitan Police says armed officers have been sent to the scenes and shots were fired. They did not say if officers fired the shots. The force has tweeted a warning telling people in the area to run to safety, hide and then call police if it is safe to do so.

A spokesman for Prime Minister Theresa May says she is being briefed on the incident at London Bridge. The spokesman says the prime minister is in contact with officials and is being regularly updated.

Read: Pedestrians hit on London Bridge; police say terror attack

May has not commented yet but in the past she has convened her emergency security Cabinet known as Cobra after major incidents.

Britain's official terror threat had recently been lowered from "critical" after a bombing killed 22 people at an Ariana Grande concert in Manchester.

US President Donald Trump's spokesman says Trump has been briefed by his national security team and he will be provided with updates.

British transport police say there are reports of multiple casualties following a major incident on London Bridge.

Nick Brandon of the British Transport Police control room says he has received reports of an incident possibly involving a knife and a vehicle.

Witnesses have reported seeing people hit by a vehicle on London Bridge. Police say they're responding to an incident there and another at Borough Market, a busy area of pubs and restaurants nearby. He said the seriousness of the injuries is not yet known.

London police are treating injured people on a small street some 500 meters (yards) southwest of London Bridge, where witnesses say pedestrians were hit by a vehicle and police say they are responding to an incident.

Britain's Press Association news agency says members of the public were told to run away as fast as they could from the area, which is filled with restaurants and pubs.

Nick Archer, who was in the London Bridge area, says he came out of a bar and looked to his left and saw a man lying on the ground. He thought the person had been drinking, but then police vans flew by.

London police say they are responding to an incident at Borough Market, a popular tourist area with restaurants and bars a short distance from London Bridge, where a vehicle is reported to have hit pedestrians.

The Metropolitan Police force says armed officers are responding at both scenes.

Witnesses have reported seeing injured people on the ground on the bridge. Police have closed a nearby railway station and told people to get away from the area.

London's transportation authority has closed three London Underground stations near London Bridge, where police say they are dealing with an incident and witnesses report seeing a vehicle hitting pedestrians.

An eyewitness tells Sky News he saw people who seemed to have been run over and people being placed in an ambulance covered in blankets.

London Metropolitan Police have said only that they are dealing with an incident on the bridge, and London Mayor Sadiq Khan tweeted that people should follow police on Twitter for updates.

Another eyewitness tells Sky he heard a burst of gunfire during the incident. British police say they are dealing with an "incident" on London Bridge.

Witnesses report a vehicle hitting pedestrians and injured people on the ground. Transport for London says busy London Bridge station has been closed at the request of police.