A British man and two Kenyans have been charged with handling explosive materials by a court in Kenya's coastal city of Mombasa.
Jermaine Grant had already received a three-year jail sentence for being in the country illegally after using false documents that claimed he was a Canadian called Peter Joseph.
Police say the three were arrested with a Kenyan woman in December in a house with chemicals commonly used to make bombs.
Grant's arrest was followed by a warning from the British government that it believed militants linked to Somalia's al-Shabab group were about to carry out a terror attack in Kenya.
The al-Qa'ida affiliated al-Shabab said today it took several hostages in a raid in northern Kenya that killed at least six people.
Three policemen, a civil servant and a primary school teacher were among the six killed in the attack late on Wednesday, said police.
A pregnant woman was also reported killed.
The press release from the militant group did not specify how many hostages had been taken from the northern town of Gerille, near the Somali border, but said their identities would soon be released.