Maiduguri - A blast targeting a military patrol vehicle in the Nigerian city where a radical Islamist group is based killed two civilians on Wednesday, the military said.
"An improvised explosive device targeting [a military] patrol team exploded at [the] post office roundabout in Maiduguri," Lieutenant Colonel Sagir Musa said in a statement.
He said that while the military suffered no casualties, two civilians died in addition to the attacker, without clarifying whether the assailant was a suicide bomber or if he died inadvertently.
Maiduguri is considered the home base of Islamist group Boko Haram, blamed for hundreds of deaths in northern Nigeria since 2009, including scores of attacks in Maiduguri.
Separately, the military said that hundreds of leaflets were distributed around the north-eastern city overnight on Tuesday, warning that Boko Haram had not declared a ceasefire, as reported by some media.
A ceasefire declaration last month from a man claiming to represent Boko Haram was viewed with suspicion by some, as there were questions as to whether Sheikh Muhammed Abdulazeez Ibn Idris was a legitimate envoy or a fraud.
The declaration was widely covered in the local media.
While it was not clear if the leaflets contained a legitimate message from Boko Haram, the group has in the past distributed such documents overnight to communicate with residents.
The group says is it fighting to create an Islamic state in Nigeria's mainly Muslim north. Most people in the south of the country, Africa's most populous, are Christian.
France has said that Boko Haram is to blame for the abduction on Tuesday of seven French nationals in Cameroon near the northern border with Nigeria, not far from Maiduguri.
The group has never acknowledged abducting Westerners in the past and Nigeria has avoided comment on the French claim.