Five men were arrested in pre-dawn raids Friday on the second day of Pope Benedict XVI's trip to Britain, police said.Several homes were being searched for additional evidence. No hazardous materials or weapons have been found thus far.
The men, between the ages of 26 and 50, were detained under the Terrorism Act at a business in central London. They were being questioned at a London police station and had not been charged.
Police said an initial search of the business and other properties did not uncover any hazardous items.
Police said they received information about a potential threat against the pope overnight, prompting the armed operation to arrest the men early Friday morning.
The BBC reported that the five suspects worked as street cleaners for Veolia Environment Services, a company that is contracted by Westminster Council. They were arrested by armed officers as they prepared to start their shift, the BBC said.
Landmarks within Westminster’s boundaries including Buckingham Palace, Britain's Houses of Parliament, Westminster Abbey and Westminster Cathedral, the Catholic headquarters of the United Kingdom.
It is not clear whether the investigations relate to a plot against the Pope himself, an element of the visit or events or other matters that may be connected to the visit. Most of the men are understood to be Algerian.
In the statement, the Metropolitan 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.