Britain extended a deadline on Tuesday for holding nine terrorism suspects seized in hasty raids last week after a U.S. security alert based on a Pakistani undercover source whose name was compromised. Police said magistrates had given them an extra week to question the suspects, being held at London's high-security Paddington Green station. When the final extension expires next Tuesday, the men, aged from 19 to 32, must be charged or freed. Britain initially held 13 suspects in raids across the country on Aug 3. Four have since been released or charged with non-terrorism offences. Police sources have said the arrests were carried out more hastily than planned, and experts say this may be because a sting operation had to be aborted after an undercover Pakistani source was named in U.S. newspapers. Instead of the usual procedure of seizing suspects at home at night when they can offer less resistance, they were captured in daylight, some dragged out of shops, others held after a high-speed car chase. Britain has arrested more than 600 people under terrorism laws since the Sept. 11, 2001, attacks in the United States. But fewer than 100 have been charged and only 15 convicted of terrorist offences.