**Nigeria’s President Umaru Yar’Adua has ordered an investigation into last week’s Islamist uprising, which left hundreds dead.**He said this would include the death of the sect’s leader, Mohammed Yusuf.
Mr Yusuf was arrested but then shot dead. Police say he was killed in a shoot-out when he tried to escape but some say he was executed.
His Boko Haram sect attacked several police stations across the mainly Muslim north.
The sect said it was fighting against Western education and believed Nigeria’s government was being corrupted by Western ideas and wanted to see Islamic law imposed across the country.
Meanwhile, the inspector-general of police, Ogbonaya Onovo, denied that his force took part in extrajudicial killings.
Police say Mr Yusuf was shot dead in an exchange of fire during the process of his arrest.
Boko Haram launched simultaneous attacks on police stations in different parts of northern Nigeria - but its militants were mainly armed with machetes and hundreds were killed by the security forces.
Mr Yar’Adua said the killing of Mr Yusuf would be investigated “together with the overall events that have happened”, AFP news agency reports.