Ansyaad Mbai, the head of Indonesia's anti-terror unit, told the BBC that Mr Ba'asyir was detained on terrorism charges.
Kenyan police say their anti-terror unit is questioning two Britons arrested near the border with Somalia.
"It seems that the explosive was detonated as our anti-terror unit vehicle passed by, carrying 21 policemen," Mr. Capkin said.
"At one point, a team from our anti-terror unit was called in to deal with a man carrying a firearm.
A British team was present in the room, including officers from the Metropolitan police's anti-terror unit along with Israeli officials.
Kenya's security forces, including a police anti-terror unit which receives funding from Britain and the US, have abducted and murdered scores of terror suspects in recent months, activists and relatives of those missing have told The Independent.
Authorities in Oslo were getting ready to send an anti-terror unit to the scene but called off the deployment after receiving reports that the suspect had been arrested.
That's a relief, although it begs the question: what on earth is a crack anti-terror unit doing flying helicopter patrols around Telfs with live ammo and the safety off?
The five suspects were apparently arrested on Friday night shortly after the attack, in a raid in Nablus by the Israeli army's Duvdevan unit, a police anti-terror unit, and the Shin Bet.
Wycliffe Makasembo, Adebolajo's legal representative in Kenya, said that the British high commission sent a letter to the country's anti-terror unit after his arrest informing them Adebolajo was "a clean man", which is why he was then released.
Some media outlets have reported that members of Indonesia's anti-terror unit Detachment 88 are also involved - highly unusual for the transfer of two drug convicts.
