NAIROBI, Kenya -- A suspect in last week's savage killing of a British soldier on a London street was arrested in Kenya in 2010 while apparently preparing to train and fight with al-Qaida-linked Somali militants, an anti-terrorism police official said Sunday.
Michael Adebolajo, who was carrying a British passport, was then handed over to British authorities in the East African country, another Kenyan official said.
The information surfaced as London's Metropolitan Police said specialist firearms officers arrested a man Sunday suspected of conspiring to murder 25-year-old British soldier Lee Rigby. Police gave few details about the suspect, only saying he is 22 years old.
The arrest brought to nine the number of suspects who have been taken into custody regarding Rigby's horrific killing in London. Two have been released without charge, and one was released on bail pending further questioning. No one has been charged in the case.
The British soldier, who had served in Afghanistan, was run over, then stabbed with knives in the Woolwich area in southeast London on Wednesday afternoon as he was walking near his barracks.
Adebolajo, 28, and Michael Adebowale, 22, are the main suspects in the killing and remained under armed guard in separate London hospitals after police shot them at the scene.
In 2010, Adebolajo was arrested with five others near Kenya's border with Somalia, Kenya's anti-terrorism police unit chief Boniface Mwaniki told The Associated Press. Police believed Adebolajo was going to work with Somali militant group al-Shabab.
Mwaniki said that Adebolajo was deported from Kenya after his arrest in 2010. Kenya's government spokesman said he was arrested under a different name, and taken to court before being handed to British authorities.
"Kenya's government arrested Michael Olemindis Ndemolajo. We handed him to British security agents in Kenya, and he seems to have found his way to London and mutated to Michael Adebolajo," spokesman Muthui Kariuki said. "The Kenyan government cannot be held responsible for what happened to him after we handed him to British authorities."
Kariuki said Adebolajo was traveling on a British passport, but he could not confirm if it was authentic.
When asked whether British security agents and embassy officials had handled Adebolajo in Kenya, a British Foreign Office spokeswoman said in a brief statement: "We can confirm a British national was arrested in Kenya in 2010. The Foreign and Commonwealth Office provided consular assistance as normal for British nationals." She did not elaborate and said she did not have information about what had happened to Adebolajo then.
Rigby's grieving family visited the scene of his killing in London on Sunday, pausing for a few moments in reflection and laying flowers to join the hundreds of floral tributes already left at the nearby Woolwich Barracks by well-wishers.
The soldier's gruesome slaying has horrified Britain, partly because it was captured by witnesses' cellphones. A video picked up by British media showed one of the suspects, with bloodied hands, making political statements and warning of more violence as the soldier lay on the ground behind him.
Hardline Muslim leaders say the man in the video was Adebolajo, and they have described him as an Islam convert who used to take part in London demonstrations organized by British radical group al-Muhajiroun. The group catapulted to notoriety after the Sept. 11, 2001, attacks by organizing an event to celebrate the airplane hijackers, and was banned in Britain in 2010.
More than 20 supporters of the group have been arrested over terrorism offenses, including a foiled plot to blow up central London nightclub Ministry of Sound and a bomb attack on London's Territorial Army base.
Abu Nusaybah, a friend of Adebolajo's, has asserted in a BBC interview that Adebolajo became withdrawn after he allegedly suffered abuse by Kenyan security forces during interrogation in prison there. Nusaybah was arrested by counter-terrorism police outside the BBC's London studios Friday night immediately after recording the interview, and police said Sunday his detention has been extended to May 31.
Anti-terrorism chief Mwaniki on Sunday rejected Nusaybah's allegations. Mwaniki said at the time there were no indications of torture or abuse, but that the unit would further investigate.
Mwaniki said dozens of foreign youth are arrested every year attempting to cross the Kenyan border to join al-Shabab, which claims to be fighting a jihad, or holy war, against the Somali government and African Union forces.
Al-Shabab controlled Mogadishu from roughly 2007 to 2011. The group still dominates most of south central Somalia but has seen its territory reduced after military pushes by African Union and Somali forces.
According to an August U.S. State Department report on terrorism, al-Shabab continues to maintain training camps in southern Somalia for young recruits, including Americans who have traveled there from Somali communities in the United States.
The camps have churned out dozens of bombers who've launched attacks in and outside Somalia.
Al-Shabab boasts several hundred foreign fighters, mostly East African nationals and veterans from the Iraqi and Afghanistan wars.
British officials have been on the lookout for security threats originating from Somalia for some years.
In a speech in 2010, Jonathan Evans, then head of Britain's MI5 domestic security service, warned that "a significant number" of British residents were training in al-Shabab camps to fight in the insurgency there.
"I am concerned that it is only a matter of time before we see terrorism on our streets inspired by those who are today fighting alongside al-Shabab," he said.
Meanwhile, London police said a man in his 20s was stabbed Sunday in the Woolwich area of London close to where Rigby was killed, momentarily rattling people in the area. But Scotland Yard said the stabbing was not related to terrorism or to Wednesday's slaying. A spokesman said the victim was not a soldier, and one man was arrested for assault.
Deputy Assistant Commissioner Stuart Osborne, head of Scotland Yard's counterterrorism command, said officers are pursuing CCTV, social media, forensic and intelligence leads in the Rigby investigation. He appealed for anyone who knew the two attackers to contact police with information.
British officials said Sunday they are also setting up a new terrorism task force to tackle radical preachers and extremism. Home Secretary Theresa May said the group will look at whether new powers and laws are needed to clamp down on religious leaders and organizations who promote extremist messages and who target potential recruits in British jails, schools and mosques.