Two men questioned over a suspected attempt to recruit a cell of British suicide bombers have been released without charge.
Twelve other men remain in custody after being arrested in anti-terror raids that started at a Chinese restaurant in Borough, south London.
Today police were given extra time to quiz three of the twelve until Monday.
The custody deadline for the other ten is on Friday, when officers must either charge or release them, or request an extension from the courts.
A Met spokesman said it was "not unusual" for people to be freed without charge in terror investigations.
"In all operations, some people may be released early without charge while others may remain in custody for further investigation.
"This ... is to be expected in large and complex criminal enquiries where a number of arrests have taken place."
Police have raided 17 homes across south and east London, as well as an Islamic school near Tunbridge Wells.
Searches on the 54-acre grounds of Jameah Islamiyah school near Crowborough, East Sussex, could continue for weeks, police said.
The suspects are thought to have attended regular weekend camps at the school, which allegedly included extremist lectures and survival lessons.
A lake and woodlands on the grounds are also to be trawled.
Detectives said the arrests, all on suspicion of the commission, preparation or instigation of acts of terrorism, were not linked to the alleged plane plot or the July 7 bombings.
Scotland Yard and MI5 watched the group for months before swooping on Friday night.
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