Suspected Islamic militants have killed 44 people praying at a mosque in north-east Nigeria, the latest in a spate of violence blamed on religious extremists in the country.

The killings occurred on Sunday morning at a mosque in Konduga town, 22 miles outside Maiduguri, the capital of Nigeria's Borno state.

A state security service agent and a member of a civilian vigilante group working with the military said they counted the bodies at the mosque after the attack.Usman Musa of the civilian group says four of its vigilantes were also killed when they responded to calls for help.

Along the way from Maiduguri to Konduga, the civilian activists encountered "fierce resistance from heavily armed terrorists", Musa said.

Nigeria has been besieged by an Islamic uprising led by the Boko Haram militant group, which has gone after a range of targets including Christians outside churches, teachers and schoolchildren and moderate Muslim clerics who have spoken out against extremism.

Nigeria declared a state of emergency in much of the north-east on 14 May to fight the Islamic uprising, whose goal is to impose Islamic law across a country divided almost equally between the predominantly Muslim north and the mainly Christian south.

The insurgency poses the greatest threat in years to the security of a country of more than 160 million, which is Africa's biggest oil producer and most populous nation.