Three people arrested over the murder of a soldier in the London suburb of Woolwich have been released on bail, while the two main suspects remain in hospital, police say.
Michael Adebolajo, 28, and Michael Adebowale, 22, both British Muslim converts from Nigerian Christian families, remain under armed guard at separate London hospitals.
They are "in a stable condition and will be formally interviewed when it is possible to do so", Scotland Yard said on Monday.
The latest development came as Kenyan police revealed that one of two men arrested over the murder of the soldier, 25-year-old Lee Rigby, was detained in Kenya in 2010 on suspicion of seeking to train with an al-Qaeda-linked group in Somalia, Kenyan police say.
Confirmation that Adebolajo was held in Kenya and deported to Britain will intensify calls for UK spy agencies to explain what they knew about the suspect and whether they could have done more to prevent Rigby's killing near a barracks in Woolwich on Wednesday.
The UK government has confirmed that it provided Adebolajo with consular assistance when he was arrested.
The Kenyan government initially said Adebolajo had never visited Kenya. But on Sunday, Boniface Mwaniki, head of Kenya's anti-terrorism police, said Adebolajo was arrested in November 2010 and deported to Britain.
"He was arrested with a group of five others trying to travel to Somalia to join the armed group al-Shabab," he told the Reuters news agency.
The group wants to impose a strict version of Islam across Somalia.
Surveillance camera footage
Meanwhile, detectives are still sifting through CCTV footage, social media, forensic evidence and intelligence reports relating to Rigby's killing .
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"This remains an ongoing investigation, focused upon pubic safety and identifying any others that may be involved," Stuart Osborne, Scotland Yard's head of counterterrorism, said.
"The investigation is progressing well, but there is still a lot more work to be done."
Separately, police won judicial approval on Sunday to question a 31-year-old man for another five days on suspicion of the commission, preparation or instigation of acts of terrorism.
Abu Nasaybah was arrested on BBC premises late Friday shortly after giving an interview about his friendship with Adebolajo, in which he claimed MI5 had tried to recruit the murder suspect.
Despite calls for calm from Prime Minister David Cameron and Muslim and Christian leaders, one charity said it had recorded a surge in anti-Muslim incidents, while there have also been a number of attacks on mosques in recent days.
An Islamic cultural centre in Grimsby in northeast England was hit by petrol bombs on Sunday night, although police said it was "too early to speculate" on why the fire was started.
Two people have been arrested over the attack, which did not result in any injuries, and police said they were monitoring messages posted on social networking sites that "appear to be an attempt to incite trouble".
Eleven teenagers aged 16 or 17 were arrested for attacking the Grimsby mosque and cars parked outside on Thursday night after a party nearby got out of control, police said.
The British government also said it is forming a group to combat Muslim religious leaders and others whose words could encourage violence.
Cameron's office said the group aimed to fight radicalism in schools and mosques, tighten checks on inflammatory internet material, and disrupt the "poisonous narrative" of ultra-conservative religious leaders.
Tony Blair, as Britain's prime minister, had tried to tighten rules against preachers promoting violence after the London bombings in 2005 that killed 52 commuters.
The measures stirred a long debate over how to balance free speech and civil rights with a strong counterterrorism strategy.
The Muslim Council of Britain, a religious umbrella group, said new government measures risked "making our society less free, divided and suspicious of each other".