Maiduguri - Security forces welcomed on Tuesday a ceasefire declaration by a commander of the Islamist sect Boko Haram, but said they would not lower their guard.
Sheik Abu Mohammed Ibn Abdulazeez, a man local security sources say is a Boko Haram commander, called on sect members to halt attacks that have left many hundreds dead since it launched an uprising to carve out an Islamic state in Nigeria in 2009.
But it was not immediately clear if Abdulazeez was speaking on behalf of Boko Haram leader Abubakar Shekau who has neither publicly backed, nor denounced the commander who also called for dialogue in November last year.
In a statement to journalists in Maiduguri, the sect's headquarters, Abdulazeez urged security forces to reciprocate.
"Conflicts are resolved through dialogue, hence the declaration of ceasefire by the sect's leader is a welcome development," Lieutenant Colonel Sagir Musa, spokesperson for joint military and police forces (JTF) in Borno state, said by phone.
"Be that as it may, the JFT will remain in a staging position to continue maintaining law and order... in its area of operational responsibility," he said.
The doubts over the authority of Abdulazeez raise questions about possible rifts within the secretive militant movement.
He may represent only one faction within Boko Haram, which is seen as the main security threat to Africa's leading energy producer.
Hours before he spoke, gunmen in Borno state killed eight people in an attack that bore the hallmarks of Boko Haram, but which could also have been one of several criminal gangs profiting from the growing lawlessness in Nigeria's northeast.
The timing of the alleged ceasefire has been seen as curious given Nigeria's involvement in military efforts to dislodge Islamists in Mali, with whom Boko Haram are known to have forged links.
Security agencies had been braced for a backlash.
A spokesperson for Borno state governor Kashim Shettima also welcomed the ceasefire.
"The governor has regularly advocated that, unless we want to engage in an endless war, the best way out of the crisis is dialogue," his spokesperson Isa Umar Gusau said.
President Goodluck Jonathan has alluded to links between Boko Haram and Saharan Islamists as a reason for joining efforts by allied French and West African forces fighting them in Mali.
But critics say Nigeria's insurgency is largely a home-grown problem that can only be resolved with a political settlement.