Phill Rowbottom, 38, works in IT office in central London, a short 10 minute walk from where the shocking incident unfolded.

The former Orford man was alerted to the attack by a colleague, who received notification from a news service on his phone.

Mr Rowbottom and his colleagues watched on from their office as police vehicles and ambulances sped towards the scene.

“I think some people are in shock, but it’s not like London hasn’t had things like this before,” he said.

“I think it’s going to put everyone on edge for a while.”

After the attack, Mr Rowbottom spoke to a relieved friend who works at a government office that was put into lockdown.

Despite the incident, the former south-west man said he felt safe living in London.

“I generally feel safe living in London,” he said.

“The whole place is under CCTV.”

Mr Rowbottom received a text message from his mother and assured her he was OK after news of the attack spread.

He also posted a message on Facebook letting his friends know he was safe following the incident.

Five people are dead and about 40 injured after the terror attack in which a lone assailant ploughed a car into pedestrians on a busy bridge before stabbing a police officer outside the British Parliament.

The Metropolitan Police confirmed five people had been killed, including the stabbed police officer and the attacker himself, in a chaotic incident which saw the Parliament on lockdown for hours and the heart of the British capital brought to a standstill.

About 40 people were treated for injuries, some of which are described as “catastrophic”.

The chaos began when a vehicle being driven over the Westminster Bridge mowed down a number of pedestrians, including several police officers and children, causing serious injuries and leading to at least one victim falling or jumping from the bridge into the River Thames.

The driver then crashed the car into a fence outside the Houses of Parliament, before getting out and trying to run inside.

The assailant, armed with a knife, stabbed one police officer who was guarding the building, before he was shot dead by other officers.

Despite efforts by a Conservative MP and others to resuscitate the injured police officer, he passed away.

British Prime Minister Theresa May condemned the “sick and depraved” terror attack and conveyed her condolences to the families of the victims.

“For those of us who were in Parliament at the time of this attack, these events provide a particular reminder of the exceptional bravery of our police and security services who risk their lives to keep us safe,” she said.

The attack comes on the one year anniversary of a terror attack in Brussels, in which suicide bombers killed more than 30 people at an airport and metro station.

Australian Foreign Minister Julie Bishop said she knew of no Australians involved in the attack.