Abuja - An air force helicopter crashed on Monday in an area where the military is battling Boko Haram, but there were no indications that it was shot down, a statement said.
"A Air Force Mi-35 helicopter on a training mission this afternoon, crashed due to technical fault at a location south of Bama," in northeastern Borno state, defence spokesman Chris Olukolade said in a statement.
Bama is one of the areas attacked repeatedly by the insurgents waging a deadly five-year uprising.
"It is established that the crash is not as a result of any enemy action," the statement added.
Olukolade was not available to comment on whether any air force personnel died.
Nigeria has been waging an offensive in the northeast since May last year aimed at crushing the Boko Haram insurgency.
The operation has been criticised as failing to significantly weaken Boko Haram, with the group relentlessly targeting civilians and the security forces across the region.
While Boko Haram is known to have any anti-aircraft weapons technically capable of bringing down a helicopter, there was no immediate evidence suggesting the helicopter was brought down by force.
Bama has poor mobile phone coverage and residents were not reachable in the hours following the crash.
A air force plane which was taking part in the regional effort against rebels in Mali crashed in Niger in May of last year while on a reconnaissance mission.