LONDON — Detectives have been given more time to question 14 people arrested on suspicion of running terrorist training camps across Britain.

A judge gave officers at a hearing late Sunday until September 8 to hold 11 of the suspects, who were arrested Friday and Saturday. The other three can be held until tomorrow before police must seek a further extension.

Under new British antiterrorism laws, police can hold suspects for up to 28 days before they must be charged or released.

Police allege the group ran terrorism training and indoctrination camps across Britain, including in London and in national parklands including the Lake District in northern England, a police official said.

An associate of jailed radical cleric Abu Hamza al-Masri, Abu Abdullah, is among those being questioned, the official said. She spoke on condition of anonymity as she was not authorized to discuss the case in detail.

Mr. Masri is currently serving a seven-year sentence for inciting followers to kill non-Muslims.

The 14 suspects, aged between 17 and 48, were being questioned on suspicion of committing, preparing, or instigating terrorist acts, police said.

Two other people were arrested Friday in an unrelated terrorist operation in the northern city of Manchester, police said.

Police said the arrests were not linked to last month’s alleged plot to bomb as many as 10 trans-Atlantic jets or to the July 2005 suicide bombings on London’s transit network, which killed 52 commuters and the bombers.

Detectives yesterday also continued to search an Islamic school in connection with the London arrests. Forensic specialists were sweeping buildings and woodlands and planned to search a lake on the grounds of the Jameah Islameah School, about 40 miles south of London, police said.

A lawmaker representing the area where the school is located, Charles Hendry, said Mr. Masri had visited it with a group of followers.

In the past two weeks, officials have charged 15 suspects with terrorism-related offenses over the alleged terror plot to blow up planes. Five others have been released, and five are being held without charge.