Anti-terror police have made a string of arrests after swooping on properties in London and the Home Counties this morning.

Police said the operation, which began about 6am, came after extensive planning and intelligence gathering.

Search warrants were executed at the properties, after being issued under the Terrorism Act 2000.

Officers from the Metropolitan police were joined by their colleagues from Thames Valley, Sussex, Surrey, and Bedfordshire.

"A number of people have been arrested," a police statement said.

Further details are to be released later today, as the operation continues.

This morning's raids come with security forces in Britain on a high alert level.