Maiduguri, Nigeria - The father-in-law of an Islamist sect leader who set off violence that left hundreds of people dead in northern Nigeria was shot and killed and buried in a mass grave, a relative said.
Babakura Baa, the eldest son of Baa Fugu Mohammed, said Wednesday that he believes police killed his father after he went voluntarily to a police station because he heard that authorities were looking for him.
Mohammed's daughter was one of four wives of Mohammed Yusuf, the leader of a sect that attacked churches, mosques and police stations last week, beginning a wave of violence that left over 700 dead.
Police declined to comment on the allegations by Babakura Baa.
Mohammed had given Yusuf money and land to build a mosque and a headquarters.
Mohammed went to the police four days after his son-in-law had launched his attacks on July 26 and the day after police leveled his compound in the northern city of Maiduguri, Babakura Baa said.
He said he was told his father had been executed the day after he turned himself in.
"We saw photographs of Baa Fugu's corpse with gunshot wounds, and we learnt that the body of our father was also buried alongside others in a mass burial last Saturday," he said.
Borno State Police Commissioner Christopher Dega declined to comment, and his spokesman did not answer telephone calls.
Yusuf's Boko Haram sect - the name means "Western education is sacrilege" - campaigned for the abolition of Western education and the implementation of strict sharia law.
Extrajudicial killings are very common in Nigeria.
Yusuf himself was shot dead by police after being captured alive.