Two more suspects were charged on Wednesday over an alleged plot to bomb as many as 10 U.S.-bound airliners, British police said.
Two other suspects were released without charge and detectives had a few hours remaining to decide whether one other still held in custody would be charged with offenses or released, a spokeswoman for London's Metropolitan Police confirmed.
All five suspects had been held for 28 days — the maximum length of time allowed under Britain's new anti-terrorism laws.
It was the first time police had used the detention powers since legislators passed them in December.
Donald Douglas Stewart Whyte, a Muslim convert, was charged with preparing an act of terrorism and three offenses for owning without authority an 8mm pistol, ammunition and a silencer, police said.
A Metropolitan police official said Muhammed Usman Saddique, 24, was also charged with preparing an act of terrorism, by planning to smuggle explosive aboard trans-Atlantic aircraft.
The five suspects were rounded up with 20 others in raids on Aug. 9-10.
It brought to 17 the total of people charged over the alleged plot to assemble and detonate improvised explosives on board as many as 10 U.S.-bound planes. Five others had been released.
The purported attack would have caused mass murder on an "unimaginable scale," police as said they announced arrests in early August — leading to major terror alerts in the United States and Britain, and causing major disruptions to air travel.
Eleven suspects have been charged with conspiracy to commit murder and also with preparing acts of terrorism. Two more, Whyte and Saddique, are also charged with preparing terrorism acts.
Four others are charged with lesser offenses, including withholding information about planned terrorism.
Trial in 2008 at earliest
Prosecutor Colin Gibbs told a hearing at London's Central Criminal Court on Monday that 11 suspects facing the most serious charges would not be brought to trial before 2008 as officials sift through evidence from across the world.
Investigators continue to study evidence including alleged explosive materials, computers, travel and phone records and other documents, Gibbs said.
Peter Clarke, London's chief counterterrorism detective, has disclosed that police seized hydrogen peroxide, bomb-making components and six martyrdom videos during searches of 70 homes, businesses, vehicles and open spaces, including a stretch of woods in High Wycombe.
British Home Secretary John Reid has signaled he now intends to seek parliamentary support to extend the maximum detention limit for people arrested on suspicion of terrorism beyond 28 days.
Lawmakers agreed on the limit last December, after Prime Minister Tony Blair failed to persuade legislators to agree to a 90-day detention period — his first ever defeat in Britain's House of Commons.
