Warnings that a terror attack was due to be launched against Britain on Monday were a hoax, police have said.

Text messages and social media posts claiming that the London Underground was to be targeted imminently circulated across the weekend. The message read: "They think there's a terror threat and that it will happen on the tubes tomorrow around the west end area. So don't go travelling on tubes!! It's better to be safe than sorry. Please share."

It added the false claim that "every single police officer in the met has been called into work from 4am onwards".

A Metropolitan police spokesman confirmed the message was a "definite hoax" and added that it has been in circulation since at least Friday, meaning the attack predicted would have happened on Saturday.

He said: "These rumours are not uncommon. The only thing that gives them any credence is people re-tweeting them and circulating them."

The warning appears to have gone viral after the government raised the official terror threat level to "severe", meaning that a terrorist attack in the UK is "highly likely". However, Theresa May has said that there is no evidence that an attack is imminent.

Chief Superintendent Paul Brognal of the British Transport police tweeted: "Social media contains lots of rumours regarding threats to tube network tomorrow. There is no specific threat so keep calm & carry on."