U.K. Parliament attack: Four dead including assailant, police officer

Four people have died, including a police officer, and at least 20 people injured in a major

terror attack outside the Houses of Parliament here.

Mark Rowley, the head of counter-terrorism at the Met, said the police officer, who was stabbed by a lone attacker attempting

to enter the House of Commons, had succumbed to his injury. The suspect was also shot and killed, reports The Guardian.

Earlier, two other people died, when the attacker drove a vehicle into pedestrians on Westminster Bridge, near the Parliament.

At least 20 people, including three officers, were hurt in the attack on the bridge.

One woman is believed to have been thrown over the bridge into the river Thames - and later pulled alive from the water -

while another fell on to a hard surface below the bridge.

Speaking to reporters outside the central London hospital, junior doctor Colleen Anderson from St Thomas' hospital said a

female pedestrian had also died.

Here are the top developments so far:

.Five of the injured were taken to the major trauma centre at Kings College Hospital London

.Steve White, chair of the Police Federation of England and Wales, which represents tens of thousands of rank-and-file

officers, paid tribute to the officers involved in the incident

. Former prime minister David Cameron also tweeted to express shock over the incident

. London mayor Sadiq Khan has issued a statement saying that an urgent investigation is underway and his thoughts are with

those affected and their families. He also expressed his thanks to the police and emergency services for their rapid response.

.Tourists riding the London Eye were stranded on the iconic attraction when the area was locked down after a terrorism

incident near the Parliament.

. Conservative MP Tobias Ellwood gave mouth-to-mouth resuscitation to the policeman who was stabbed.

. U.S. president Donald Trump described the incident as "big news" after he was updated on the situation.

. The Met police are appealing for pictures or video footage of the incident.

. Intelligence agencies have immediately put together teams to work on identifying who was involved in the attack and whether

there was a link to a terrorist group.

. A police officer has been stabbed and his attacker shot after a major terrorist incident at the Houses of Parliament in

which several people have been injured.

. The attacker mowed down several pedestrians as he drove a grey Hyundai i40 across Westminster Bridge before crashing it into

railings then running through the gates of the Palace of Westminster and stabbing the officer.

. Witnesses said he was shot by police as he approached a second officer while clutching his knife.

. The Port of London Authority confirmed that a seriously injured woman has been recovered from the Thames river, however, it

is yet to be confirmed if she fell or jumped from the bridge.

. The House of Commons has been put in lockdown, with many MPs confined to the Commons chamber after parliamentary business

was suspended.

. Plans for a London-wide emergency have been put into place as a precaution, but police are hopeful the incidents are over.

. A Downing Street source confirmed to Guardian that Prime Minister Theresa May was "okay". May was seen being ushered into a

silver Jaguar car as what sounded like gunfire rang out at parliament during the incident at around 2.45pm.

. The police say no terrorists have got into the parliament building. They say two have been caught on Westminster Bridge, and

one officer is down.

. It has been confirmed that at least 10 patients have been treated for injuries on the Westminster Bridge.

. The London Eye, opposite the House of Parliament on the other side of Westminster Bridge, is also in lockdown, with some

being held inside the attraction's pods.

More details to follow.