Britain's parliament is on lockdown after gun shots were heard outside the Palace of Westminster, and lawmakers have suspended sessions for the remainder of the day amid what appears to be a major security alert in the city of London.

U.K. lawmaker David Lidington told Parliament that a policeman was stabbed during the attack before being shot dead by police.

The BBC is also reporting that several people were also injured along Westminster Bridge, which runs adjacent to the parliament, and police have said that at least one person was shot. 

Video footage, taken along Westminster Bridge by an onlooker and broadcast by the BBC, appeared to show at least five people begin treated for injuries along the busy roadside, with eyewitnesses saying a car deliberately targeted pedestrians. An air ambulance has landed in Parliament Square and its attending to the injured along the Bridge.

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The incident comes only hours after U.K. Prime Minister Theresa May held her weekly question-and-answer session with opposition lawmakers in the Houses of Parliament, a session that is typically attended by nearly all members of the sitting government.

It also follows an attack on female soldiers at Orly Airport in Paris Saturday in which the attacker, 39-year-old Ziyed Ben Belgacem, was shot and killed by military police.

Belgacem, who was born in France to Tunisian parents, grabbed the soldier in Orly's southern terminal on Saturday morning, put a gun to her head and seized her rifle, saying he wanted to "die for Allah". The attacker also fired at police officers earlier in the day in a northern Paris suburb.