The UK's terror threat level has been moved from "substantial" to "severe" following the recent attacks in France and Vienna. 

Home Secretary Priti Patel has said the move, which means security chiefs believe an attack is "highly likely", has been put in place as a precautionary measure.

Speaking to the BBC, she said the British people should be "alert but not alarmed" as she urged the public to remain vigilant and to report any suspicious behaviour to police. 

She said: "This afternoon The Joint Terrorism Analysis Centre (JTAC) has changed the threat level across the United Kingdom from terrorism from substantial to severe.

"The British public should be alert but not alarmed. This is a precautionary measure following the terrible incidents that we've seen in France last week and the events that we saw in Austria last night.

"As I've said before, we face a real and serious threat in the UK from terrorism.

"I would ask the public to remain vigilant and to report any suspicious activity to the police."

A shooting in Vienna on Monday evening saw four people die as a result of the attack.

Last week, three others died in a knife attack in Nice, France after a teacher was murdered in Paris last month.

Home Secretary Priti Patel added that significant steps had already been taken to amend powers and strengthen the tools for dealing with developing terrorist threats.

Assessments of threat levels are taken by the Joint Terrorism Analysis Centre (JTAC), part of MI5, which makes its recommendations independently from the government.