UK Parliament attack: 5 dead including cop, alleged assailant; 40 hurt

Five people were killed and 40 others injured in a "terrorist" attack in the heart of London Wednesday when a man mowed down pedestrians on a bridge, then stabbed a police officer outside parliament before being shot dead.

Police guarding the iconic House of Commons building shot the man but several people were left with "catastrophic" injuries on Westminster Bridge, a busy traffic junction popular with tourists with views of Big Ben.

The car crashed into the railings outside the heavily guarded parliament building and witnesses described a man leaping out of the vehicle into the grounds of parliament and stabbing a police officer.

The incident comes with Europe on high alert after a series of deadly jihadist attacks and exactly a year after jihadists killed 32 people in a bomb attack in Brussels.

The parliament building was immediately sealed off and MPs and staff ordered to remain inside. "We are treating this as a terrorist incident," police said in a statement.

Those dead included the police officer and the attacker, authorities said. David Lidington, the British minister responsible for arranging government business, told MPs: "It seems that a police officer has been stabbed, that the alleged assailant was shot by armed police." Prime Minister Theresa May is safe, her Downing Street office said, and was preparing to chair a meeting of the government's COBRA emergencies committee.

She was seen being driven away from parliament. Police cordoned off a large area in Westminster and tourists on the London Eye, a popular tourist attraction, were stuck 135 metres (443 feet) in the air for around an hour during the incident. The local Underground station at Westminster was also closed off.