Terrorism threat level unchanged, London police

Britain has not raised its national terrorism threat level nor a separate threat gauge for airports and railway terminals, police said after reports that security had been stepped up at transport hubs.

London's Metropolitan Police, the force responsible for coordinating counter-terrorism nationally, said it had no knowledge of the threat level being raised from "substantial" to "severe," the second highest level, at major airports and railway terminals, as reported by the BBC and other media.

The separate national threat level has been at "severe" for the past year, the police said.

"The threat level to the UK is at severe, which means that an attack is highly likely, and it has been there since January 2010," a Metropolitan Police spokesman said.

"We never discuss security. We never say its been stepped up or stepped down -- so I really don't know where this has come from," he added.

Threat levels for specific national infrastructure sectors are not normally made public.

The Home Office (interior ministry) said that if there was any intelligence of an imminent threat or a plot under way the threat level would be raised to its highest level, "critical."

However a spokesman said there was a "continuing need for everyone to remain vigilant and to report any suspicious activity to the police."