Up to 11 people have been killed in multiple blasts and targeted attacks orchestrated by a Muslim sect in Nigeria's restive northeast.
Mohammed Abubakar, the Borno State police chief, said on Tuesday that members of the group locally known as Boko Haram detonated bombs at two police stations and at St Patrick's Church in the city of Maiduguri.
The multiple blasts come a day after motorcycle-mounted gunmen shot dead Sheik Ibrahim Birkuti, a cleric from a rival sect.
The police also blame Boko Haram for killing the cleric on Monday at his home in the town of Biu, south of Maiduguri. Birkuti had been critical of Boko Haram's violence.
Boko Haram has pushed for the implementation of sharia, or Islamic law, in Borno State. The group has vowed to keep killing people believed to support the establishment until sharia is adopted alongside other demands.
Nigeria, a nation of 150 million people, is divided between the Christian-dominated south and the Muslim-majority north. A dozen states across Nigeria's north already have sharia in place, though the area remains
under the control of secular state governments.
String of attacks
Boko Haram has been blamed for a rash of killings which have targeted police officers, soldiers, politicians and clerics in Nigeria's north over the last year.
The group has also attacked churches and engineered a massive prison break. However, authorities say attacks intensified after April 26 gubernatorial elections kept the same political party in power.
Kashim Shettima, the governor-elect, promptly reached out to the sect members to calm tensions by offering an amnesty, but a man claiming to speak for Boko Haram told the BBC last month that the group was rejecting its offer.
In a separate and more recent interview with BBC's Hausa language service, a man claiming to speak for Boko Haram claimed responsibility for three blasts that rocked two cities in Nigeria's north and a town close to the
capital hours after the inauguration of Nigeria's president Goodluck Jonathan, a Christian from the southern part of the country.
The National Emergency Management Agency said that 18 people died in the May 29 attacks.
Boko Haram was thought to be vanquished in 2009 after Nigeria's military crushed its mosque into concrete shards, and its leader was arrested and died in police custody. But now, Maiduguri and surrounding villages in Borno state again live in fear.
Routine attacks mean that residents are subjected to searches at dozens of checkpoints. Drivers have to come out of their vehicles, along with their passengers, and walk with their arms raised to prove weapons are not hidden in their clothing.