Home secretary Amber Rudd has confirmed that Manchester bomber Salman Abedi was a known figure to the UK's security services.
Speaking after the UK's threat level was upgraded to "critical", meaning a new attack may be imminent, Rudd told Sky News this morning that "people are likely to see some military on the streets", but declined to provide further detail.
Rudd said that Abedi was "known up to a point by the intelligence services", adding that she expected more information to come to light, but declined to expand on whether Abedi was on a specific terror watch list.
She also urged members of the public to be "a bit more vigilant than usual", adding that security services had foiled 13 attacks since 2013.
The home secretary added that she expected the "critical" threat level to be temporary, and expressed confidence that it would provide for extra security at the weekend's big sporting events, such as the FA Cup Final, due to take place at Wembley Stadium on Saturday.
Separately, Rudd told BBC Radio this morning: "It seems likely, possible, that he was not doing this on his own.
"The intelligence services and the police are pursuing their leads in order to make sure they get all the information and reduce therefore the risk."
In a statement this morning, London mayor Sadiq Khan said there would be additional police officers on the capital's streets "over the coming days", including armed officers and military personnel at key sites, while extra staff would be deployed on transport networks.
"London stands in solidarity with Manchester. Those who seek to harm and divide us through barbaric acts of terrorism will never succeed. We will never be cowed by terrorism," Khan said.
The national threat level has been raised to 'critical'. Watch my statement on what this means for Londoners today. pic.twitter.com/pOqUvbqThz— Sadiq Khan (@SadiqKhan) May 24, 2017