NAIROBI - Kenya's minister for internal security George Saitoti and his deputy were killed when a police helicopter crashed into a forest just outside the capital, the government said on Sunday.

Prime Minister Raila Odinga's spokesman said Odinga had been informed of the deaths of Saitoti and his deputy, Orwa Ojode.

A former long-serving vice president under the former President Daniel Arap Moi, Saitoti was also a presidential candidate in an election expected to be held by March next year.

A Reuters photographer counted three charred bodies at the scene of the crash in a forest in the Ngong area just outside of Nairobi.

Debris of the burnt-out blue police helicopter were strewn in the brush where government officials and curious locals jostled to catch a glimpse.

It was not immediately clear what caused the crash. More people were feared to have been on board the helicopter.

Saitoti, an ally of President Mwai Kibaki, was the leading government voice against Somali militants al Shabaab, often visiting the scenes of grenade attacks inside Kenya and vowing the east African nation would crush the group.