Authorities in the capital of Nigeria's Borno state said on Monday that 18 bodies had been recovered at two outlying villages since the clashes late on Sunday.

"The victims were killed while trying to escape the fight between the insurgents and the military," said the region's State Emergency Management Agency (SEMA), which described the incident as an "attack."

It emerged later on Monday that Boko Haram fighters had also attacked a military base in the Cashew Plantation area on the outskirts of Maiduguri.

"Eighteen Boko Haram terrorists on foot attacked the military base while seven suicide bombers targeted residents of nearby Bale Shuwar and Alikaranti villages at 8:50 p.m. (1850 UTC)," an officer who asked not to be identified told the news agency AFP.

"The terrorists fired mortars at troops," the officer said.

If so, the incident would rank as the most serious since Nigeria's government recently announced that it was in talks with the jihadi insurgents.

It was not immediately clear if the casualty figures accounted only for civilians or included the jihadis and soldiers as well.

Teenage bombers

Maiduguri was the origin of Boko Haram, a hardline Islamist group, whose insurgency over nine years has claimed at least 20,000 lives and displaced more than 2 million residents.

Last Friday, at least one resident and four teenage girls reportedly wearing suicide bomb vests were killed at the settlement of Zawuya, also on the city's outskirts.

Residents estimated that the female bombers were aged between 13 and 18 and said two people, a boy and a woman, were killed during the attack.

In the week before last, Nigerian President Muhammadu Buhari said his government was offering amnesty to "repentant" jihadis as 100 schoolgirls were returned to the town of Dapchi.

Nigerian officials denied paying a ransom for their release.

Buhari's information minister, Lai Mohammed, revealed that a temporary ceasefire had been declared as part of "intense back channel" negotiations to free the hostages.

They had been abducted on February 19. It had been the largest mass kidnapping since 2014 when over 200 schoolgirls were taken from Chibok.

Security officials had warned that talks would be difficult because Boko Haram is split into competing factions.

Involved in the Dapchi abduction was the so-called Al-Barnawi faction. Still reportedly adverse to talks is another faction, known as Shekau.

ipj/msh (AFP, Reuters)