LAGOS, Nigeria — A radical Islamist sect has claimed responsibility for attacks on military bases in a central Nigerian city at the heart of ethnic and religious unrest in the country.

A spokesman for the sect known as Boko Haram told The Daily Trust newspaper of Nigeria's Muslim north that it carried out Tuesday's attacks on an army and air force base in Kaduna. Military officials say only a bomber was killed in the attack, though witnesses saw soldiers in blood-drenched uniforms.

The sect also denied sending a video message aired Tuesday on the state-run Nigerian Television Authority in which they purportedly accepted an offer to negotiate for peace with the oil-rich nation's weak central government.