Ibrahim Muktar Said, 27, who is accused of trying to detonate a bomb on a bus in east London, and Ramzi Mohammed, suspected of attempting the Oval underground train bombing, were arrested in raids in west London on 29 July, police said.

The pair were due to appear in court on Monday along with bombing suspect Yassin Hassan Omar, 24, who is suspected of trying to bomb an underground train near the Warren Street station.

The three face charges of conspiracy to commit murder, attempted murder, making or possessing an explosive substance with intent to endanger life or cause serious injury, and conspiracy to use explosives.

They will appear before Bow Street Magistrates' Court, sitting at Belmarsh, in southeast London, in a court building adjacent to a high-security prison.

A fourth suspect arrested in Rome awaits extradition. He is known as Osman Hussain or Hamdi Issac, and is being held there on international terrorism charges.

Other charges

British police, enforcing a US warrant, on Sunday arrested Haroon Rashid Aswat, a British citizen of Indian descent, who had been deported to the UK after Zambian authorities held him in connection with the London bombings.

He is suspected to have links to al-Qaida and was also due in court on Monday.

Also due to appear in court at Belmarsh was Manfo Kwaku Asiedu, 32. Police charged him late on Sunday with conspiracy to murder passengers on London's transit system on 21 July and conspiracy to cause explosions likely to endanger life.

Three other men were also due in court on Monday in connection with the case.

Police have charged Siraj Yassin Abdullah Ali, 30, Wharbi Mohammed, 22, and Asias Girma, 20, with assisting people in evading arrest.

British prosecutors said on Sunday they were also considering treason charges against any Islamic extremists who express support for terrorism.