Five men were today arrested over a terrorism threat in connection with the Pope's visit, Scotland Yard said.

The arrests were made at 5.45am in London by the Metropolitan Police.

Business and residential premises across the capital are being searched as detectives question five men aged 26, 27, 36, 40 and 50 at a police station in central London.

Unconfirmed reports said the men were of Arabic origin.

As news of the arrests broke, the Pope was attending an assembly with thousands of schoolchildren at St Mary's University College in Twickenham.

A police spokeswoman confirmed no addresses in the west London or Twickenham areas were being searched.

She said the searches were focused on north and east London.

The arrests were made after counter-terrorism officers received intelligence of a potential threat.

The five were arrested on suspicion of the commission, preparation or instigation of acts of terrorism under the Terrorism Act 2000.

Nothing has been found by police searches yet, Scotland Yard said.

In the statement, the Met Police said: "Today's arrests were made after police received information following initial inquiries by detectives. A decision was made to arrest the five men.

"Following today's arrests policing arrangements for the papal visit were reviewed and we are satisfied our current policing plan remains appropriate. The itinerary has not changed. There is no change to the UK threat level."