Kano: Gunmen believed to be Islamists from Nigeria’s Boko Haram insurgent group killed 42 people, mostly students, in an overnight attack on a secondary school in restive Yobe state, a medical worker and residents said on Saturday.

“We received 42 dead bodies of students and other staff of Government Secondary School [in] Mamudo last night. Some of them had gunshot wounds while many of them had burns and ruptured tissues,” Haliru Aliyu of the Potiskum General Hospital said.

Mamudo is some five kilometres from Potiskum, the commercial hub of Yobe State which has been a flashpoint in the Boko Haram insurgency in recent months.

“From accounts of teachers and other students who escaped the attack, the gunmen gathered their victims in a hostel and threw explosives and opened fire, leading to the death of 42,” Aliyu said.

He said security personnel were combing the bushes around the school in search of students who were believed to have escaped with gunshot wounds.

“So far six students have been found and are now in the hospital being treated for gunshot wounds,” he added.

A local resident who did not want to be named confirmed the attack.

“It was a gory sight. People who went to the hospital and saw the bodies shed tears. There were 42 bodies, most of them were students. Some of them had parts of their bodies blown off and badly burnt while others had gunshot wounds,” he said.

He said the attack was believed to be a reprisal by the Boko Haram Islamists for the killing of 22 sect members during a military raid in the town of Dogon Kuka on Thursday.

Nigeria declared a state of emergency in three flashpoint states of Adamawa, Borno and Yobe in mid-May as it launched a major offensive to end the insurgency.

Violence linked to the Boko Haram insurgency has left some 3,600 people dead since 2009, including killings by the security forces.

Boko Haram which means “western education is evil” has killed hundreds of students in attacks on schools in the tense region in recent months

Under the leadership of fiery militant Abu Bakar Shekau, Boko Haram rejects all Western cultural influences like modern schooling and yearns for the days when much of West Africa was ruled by great Islamic empires thriving off trans-Saharan trade.

Potiskum is in Yobe state, one of three covered by a state of emergency declared by President Goodluck Jonathan in May, when he ordered extra troops into the region to try to quell a rebellion seen as Nigeria’s biggest security headache.

The hit-and-run strikes have raised fears the seven-week-old military offensive has pushed the insurgents fighting for a breakaway Islamic state into hiding, but failed to stop them launching devastating attacks.

Suspected Islamist militants opened fire on a school in Nigeria’s northeastern city of Maiduguri last month, killing nine students, and a similar attack on a school in the city of Damaturu killed seven just days earlier.

Shifting targets of its attack as it comes under pressure has been a consistent Boko Haram tactic since the sect launched an uprising in 2009, when hundreds of members, including founder Mohammad Yousuf, were killed by security forces.

The militants have repeatedly proved masters at melting away under pressure and then re-crystalising in new forms. From a radical clerical movement, they transformed into a rebellion, forging ties with Al Qaida-linked jihadist groups in the Sahara.

Nigerian forces say their offensive has enabled them to wrest back control of the remote northeast from Boko Haram, destroy key bases and arrest scores of suspects.

But critics say no amount of force can destroy what is in part a grassroots movement feeding off discontent at bad governance and widening inequalities between a depressed north and an economically booming south.

Jonathan’s administration has offered an amnesty and peace talks to members who renounce violence, but their leader Shekau has repeatedly rejected any negotiations.