Abuja - The military said on Thursday that it had killed 20 Islamist insurgents in the restive northeast, as schools were shut in the region to prevent further attacks targeting students.
Defence spokesman Chris Olukolade said troops repelled an ambush by Boko Haram militants on Wednesday in Mafa, Borno state, epicentre of the uprising which has killed 500 people this year alone.
"Twenty insurgents died in the encounter," he said in a statement.
There was no independent confirmation of the death toll. Communication with the region has been difficult after the military switched off mobile phone networks to prevent militants from planning attacks.
Boko Haram gunmen were blamed for killing 29 people in the village on Sunday, a day after a twin blast in the state capital Maiduguri killed 35 and an attack on another village nearby claimed 39 lives.
Witnesses and an area senator claimed the soldiers deployed in the town fled when the insurgents attacked, a claim fiercely denied by the military.
Olukolade on Thursday denounced such "inflammatory pronouncements by some highly placed persons in government" (and) "commentators in and outside the country who have consistently given false and misleading remarks to describe the disposition of troops".
There have been repeated reports of Nigerian troops fleeing when confronted by Boko Haram but Olukolade insisted "the Nigerian military cannot by any standard be overwhelmed by the insurgents".
Separately, local media reported that Nigeria's information ministry will be allocated 300 million naira ($1.8 million, 1.3 million euros) to combat misinformation published in the foreign media, particularly concerning the Boko Haram conflict.
Meanwhile, in the wake of a spate of gruesome massacres of students in the northeast, the education ministry said it had shut five government colleges (secondary schools) in "high security risk areas".
Students of the schools in the states of Adamawa, Borno and Yobe would be absorbed in other government colleges, the ministry statement said.
Last week, 43 students were shot and hacked to death when suspected Boko Haram gunmen stormed Federal Government College in Buni Yadi, Yobe state.
An undisclosed number of female students was abducted during the overnight attack while the whole school was burnt down.
The traumatised students have refused to stay in their schools and colleges since the attack, which was the latest against schoolchildren by the militants.
Boko Haram, which translates roughly from Hausa as "Western education is sin", rejects a so-called Western curriculum and has burnt hundreds of schools in its four-and-a-half year fight to create an Islamic state in the Muslim-majority north.
Yobe state authorities said last October that Boko Haram attacks had razed 209 schools, causing damage worth an estimated $15.6 million (11.4 million euros).
The attacks have raised fears about the effect on education in a region that already lags behind the rest of Nigeria in social and economic development.
The country's top police officer, Mohammed Dahiru Abubakar, said on Tuesday that security agencies were "doing everything humanly possible" to prevent future school attacks.
Nigeria has since May launched a military offensive to flush out the extremists from the region, but attacks have continued, particularly in remote, border areas.
The apparent increase in violence has also prompted questions about how the militants are able to move around supposedly heavily militarised states, apparently attacking with impunity.
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