A female suicide bomber travelling on a tricycle blew herself up Friday at a market in the northeast Nigerian city of Maiduguri, witnesses said, as Nigeria and its neighbors finalize a force to combat Boko Haram jihadists.

"There had been a suicide attack on Gamboru market this morning. It was a female suicide bomber. The attack happened around 6:30 am (0530 GMT) as the grocers were arriving in the market which starts early," said Babakura Kolo, a vigilante helping the Nigerian army combat Boko Haram jihadists in the region.

Nigeria's army said Thursday it had set free 59 people held by Boko Haram, among them 29 women and 25 children, amid an ongoing offensive against the Islamist group in the country's restive northeast.

The hostages were freed as the military stormed two jihadist camps in the Konduga district of Borno on Wednesday, about 35 kilometers (22 miles) southeast of the Borno state capital Maiduguri, army spokesman Tukur Gusau told reporters.

Boko Haram Islamists slit the throats of 10 fishermen in villages near Baga on the shores of the Lake Chad in northeastern Nigeria, a leading fisherman and a resident said Thursday.

"On Monday around 4 pm (1500 GMT), Boko Haram attacked three villages on the shores of Lake Chad where they slaughtered 10 people, all of them fishermen," Abubakar Gamandi, head of the fishermen's union in Borno State, told AFP.

Nigeria said Thursday it has appointed a general to lead a new multinational task force created to fight Boko Haram in the face of a surge of devastating attacks.

The announcement came as Nigerian President Muhammadu Buhari was in Cameroon in a bid to forge a stronger regional alliance against the Islamists.

Nigerian President Muhammadu Buhari arrived in neighboring Cameroon on Wednesday for talks on how to combat the escalating regional threat from Boko Haram Islamists.

Security was tight for the 24-hour visit, after a surge of Boko Haram violence in Cameroon including an unprecedented series of five suicide bombings in the far north.

Cameroon will send around 2,000 extra troops to the north of the country to fight Boko Haram, the Nigerian jihadist movement behind bloody cross-border raids and suicide bombings, state television said Tuesday.

"Almost 2,000 extra soldiers will be deployed in the Extreme North region," on the border with northeastern Nigeria, according to the report on Cameroon Radio-Television, which gave no timetable for the operation.

Three villagers were beheaded during a weekend raid in Cameroon by Boko Haram jihadist fighters from neighboring Nigeria, security forces said Monday.

The attacks took place on Sunday in the neighboring villages of Tchebe-Tchebe and Dzaba, about 10 kilometers (six miles) from the Nigerian border, said a security agent based in the region.

A "mentally handicapped" female suicide bomber killed at least 14 people and injured 47 more at a crowded market in the northeastern Nigerian town of Damaturu on Sunday, witnesses and a hospital source said.

"Today is the market day here and at 9:50 (0850 GMT) this morning, a female suicide bomber blew herself up at the... entrance of the market where commuters were arriving," market trader Garba Abdullahi told AFP.

At least 25 people were killed in new suspected Boko Haram attacks in northeastern Nigeria, with many villagers also forced to flee their homes, residents said Saturday.

"The terrorists stormed Maikadiri around 9:00 am (0800 GMT Friday) and opened fire on hapless citizens," resident Simon Templer said.

Gunmen killed eight people in a raid on a village in northeastern Nigeria, a local resident and a vigilante said Thursday, in the latest violence blamed on Boko Haram.

The attack in Borno state Wednesday was unleashed the same day as twin suicide bombings in Cameroon and a series of blasts at two bus stations in Nigeria that left at least 50 dead.