British police arrested three men under anti-terror laws today but said they had no reason so far to link them to last week's bombings in London.
"Three people have been arrested under the Prevention of Terrorism Act at Heathrow airport," Scotland Yard Deputy Assistant Commissioner Brian Paddick told a news conference.
The arrests were made early on Sunday but he did not say whether the suspects were entering or leaving the country.
Mr Paddick said it would be "pure speculation" to link them to last Thursday's bombings on three underground trains and a bus, from which police have recovered 49 bodies and are still retrieving more from a tunnel below King's Cross station.
He said: "My understanding is these are reasonably routine arrests under the Prevention of Terrorism Act ... there is no connection that we know of at this stage."
Britain has detained more than 700 people under anti-terrorism laws since the September 11th, 2001 attacks on the United States. Of these, around 120 have been charged with terrorism offences and another 135 charged under other legislation.
Mr Paddick said police had received important information from members of the public, who had placed 1,700 calls to a special investigation hotline.
"A considerable number of these calls are proving to be very, very valuable to us," he said.
Police say the three bombs on the Underground went off almost simultaneously, making it more likely they were detonated by timers, rather than suicide bombers. That means the bombers may still be at large and could strike again, they said.
Anxious relatives continued to scour hospitals in search of loved ones missing since Thursday's blasts - the worst peacetime attacks on the British capital. Walls, bus stops and telephone boxes close to King's Cross station, scene of the worst blast, were covered with photographs of missing people and appeals for information about them.