Britain has arrested two men, one of whom is believed to have connections to the al-Qaida terrorist network.

One of the two detainees is a 24-year-old British man of Asian origin who has been arrested in a police sweep in the western English city of Gloucester.

British authorities say the action Thursday followed a long investigation. Police are believed to be looking for possible links between the man and the so-called shoe bomber（人鞋炸彈，指在鞋子中藏有炸彈進行自殺性攻擊的人）Richard Reid, who attempted to blow up a U.S. passenger plane with explosives in his shoe shortly after September 11 two years ago.

The man in charge of law and order in Britain, Home Secretary David Blunkett, calls the arrest significant.

"It is the belief of the security and Special Branch services that this man has connections with the network of al-Qaida groups. That is why he has been arrested under the Terrorism Act 2000. Obviously the forensic evidence will be absolutely crucial here, and I do not want to in any way damage the future trial. But we would not have taken these steps, if we did not believe that this individual posed a very real threat."

In Gloucester, the home of the suspect is being closely examined for explosives by special teams. Three blocks around the address have been cordoned off, and residents in 120 nearby homes have been evacuated. Deputy Police Chief Martin Baker says the charges are serious.

"The man has been arrested under Section 41 of the Terrorism Act on suspicion of involvement in the commission, preparation or instigation of acts of terrorism. He has been taken into custody into a police station in Wiltshire, and searches of the home address are ongoing."

Meanwhile in a separate investigation, a 39-year-old man has been taken into custody in Manchester.

And two premises are being searched in Blackburn, including a mosque and an Islamic learning institution.

In a joint statement, the Lancashire Council of Mosques and the Islamic College said they have cooperated with the police in their investigation.

A student read the statement on Sky television, "Islam prohibits the loss of innocent lives. In our search, we condemn all acts of terrorism, whether it's in the U.K. or anywhere else in the world."

The arrests have come at a time when Britain's terrorist threat level has been raised to the second highest under a new system introduced last year. Raising the alert level to severe generally follows new evidence of a possible al-Qaida plot.