DAKAR, Senegal -- The Nigerian military stepped up its assault on Islamist militants in northeastern Nigeria, military officials said Friday, only days after the president announced a heightened campaign against insurgents who he said had declared war on the state.
Military officials said air and ground assaults were launched against suspected bases of Boko Haram, an Islamist group, in border areas at Nigeria's northeastern edge and in a forest south of the city of Maiduguri, the group's birthplace. It was impossible to verify the military's claims independently, as phone service to the area had been cut.
Officials said a number of insurgents had been killed in the raids, but could not say how many. The military operation follows President Goodluck Jonathan's declaration of a state emergency in the country's northeast Tuesday night, which followed heightened confrontations between Islamist militants and government security forces in that hard-hit region.
The president's speech, with its promise of a stepped-up military response to Boko Haram, prompted government critics and others to warn against further large-scale civilian killings by the army and police, a pattern that has persisted since the start of the military's tough campaign against the Islamist insurgency nearly four years ago.
The United States gave some $3 million in law enforcement assistance to Nigeria last year, meets regularly with Nigerian officers on counterterrorism issues, and considers Nigeria a significant ally in the fight against Islamist extremism. But reports of civilian massacres by the military have made some officials in Washington uneasy.
On Wednesday, a State Department spokesman warned that "Nigeria's security forces must protect civilians in any security response in a way that respects human rights and the rule of law."
The scope of the current military operation appears somewhat larger than similar predecessors, although the northeast was already heavily militarized before the operation began, with numerous checkpoints on the region's roads, sandbagged military emplacements throughout Maiduguri and convoys of soldiers bristling with weapons regularly racing through the city's dusty streets.
"Advancing troops of Special Task Force have destroyed some terrorist camps sited in the forests of Northern and central Borno," said a statement from Nigeria's Defense Headquarters that was sent Friday to reporters from the country's capital, Abuja. "Heavy weapons including anti-aircraft and anti-tank guns were also destroyed in the process."
Critics wondered whether it would seriously disrupt the hit-and-run guerrilla insurgency of Boko Haram.