ARMED police are patrolling the region to provide “reassurance and resilience” in the wake of a terror attack in London.

The UK’s threat level has been raised to critical after a terrorist targeted London’s Parsons Green underground station on Friday.

Durham Constabulary’s response to the threat has been to increase armed and unarmed officers on the streets of Darlington and Durham, while Northumbria Police have deployed armed officers in Newcastle city centre.

Police said they were reviewing security measures at events this weekend to ensure there is an appropriate policing presence.

Armed police were also on duty and enhanced security checks enforced at the sold-out international T20 cricket match between England and the West Indies at the Durham County Cricket Club, Chester-le-Street on Saturday.

Those attending were issued advice to arrive early for the match.

A spokesman for the County Durham force said: “The investigation into the incident is ongoing and the public are being urged to remain calm but alert.

“The UK threat level has been raised to critical meaning an attack is expected imminently.

“As a result, there will be an increase in the number of officers on the streets, in order to provide reassurance and resilience.”

He added: “The tragic events in London and Manchester in recent months remind us that an attack can occur at any time or place and without warning.

“Members of the public are asked to be vigilant and report any suspicious activity, behaviour or concerns to police.”

A spokesman for North Yorkshire Police said: “There is currently an increased police presence in London as a result of this incident.

“This position is not being replicated in the North Yorkshire area at this time but remains under constant review in line with the ongoing investigation.”

Northumbria Police Chief Constable Steve Ashman, said it had also increased "policing presence at key locations".

He said: “This means the public will see more armed police officers at train stations, metro stations, transport hubs and other high footfall locations. This increased security is to protect and reassure the public.  

"The number of officers on duty, both armed and unarmed, has been increased significantly to provide a reassuring presence. This will remain in place for as long as is necessary.

"In some parts of the country the military may be deployed to provide visible protective security patrols, however there are no plans at this stage for the military to be deployed in the Northumbria area.

"There will be an increase in the numbers of armed police officers on patrol in our region to protect the public and that is being supported by police colleagues from the Civil Nuclear Constabulary.

"The safety and security of our communities remains our priority and we are working with partners, central government and other agencies across the country to keep the public safe.

"We will be reviewing security measures at events across the force area this weekend to ensure there is an appropriate policing presence.

"We would ask the public to remain calm but alert. If you see anything that causes you concern, report it immediately to the police."

To report any concerns in confidence call 0800 789321 or visit gov.uk/ACT. Call 999 in an emergency.

Police investigating the terrorist attack at Parsons Green have appealed for images or videos from the scene to be uploaded to ukpoliceimageappeal.co.uk.

Anyone worried about family or friends in the wake of the incident can call the Metropolitan Police on 020 7230 1212 or 101.