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.