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 neighbours 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.

There was no immediate information on the number of victims, although witness accounts suggest that there were casualties.

"From accounts we gathered from people around, the woman arrived on a taxi tricycle, as every woman grocer does. She blew herself up as soon as the tricycle stopped in the midst of other tricycles that were dropping traders off," Kolo told AFP.

A witness, who declined to be named, corroborated this account.

"I was at home when I heard a loud explosion that sent me rushing out of my house. It was coming from the Gamboru market... The place was littered with victims and burning rickshaws," the source told AFP.

Gamboru market is the second-largest in Maiduguri, capital of Borno state and birthplace of Boko Haram.

Borno and other parts of northeast Nigeria have seen a new surge in attacks since President Muhammadu Buhari took office in May vowing to end the insurgents bloody six-year campaign for an Islamic caliphate.

Many of the recent attacks have been carried out by women and girls.

A woman described by locals as mentally unstable blew blew herself up last Sunday at a crowded market in Damaturu, capital of neighbouring Yobe state, killing at least 14 people. 

Damaturu was also the scene of a triple suicide bombing on July 18 when three girls blew themselves up, killing at least 13 people as residents prepared for the Eid festival marking the end of Ramadan.

The Maiduguri market attack follows a visit this week by Buhari to neighbouring Cameroon to discuss a stronger regional alliance against the Islamists.

On Thursday, Nigeria named Major General Iliya Abbah, who previously commanded military operations in the oil-rich Niger Delta, to head a five-nation Multi-National Joint Task Force to take on Boko Haram.

The force is to comprise 8,700 troops from Nigeria, Chad, Cameroon, Niger and Benin.

In another gruesome attack reported this week, suspected Boko Haram militants slit the throats of 10 fishermen in villages on the shores of Lake Chad in northeastern Nigeria.

The Chadian army announced Friday that Chadian security forces had killed "117 terrorists" in a major, ongoing operation against the Islamists on their island hideouts in Lake Chad over the past fortnight. Two soldiers were killed and two wounded, a military spokesman said. 

Boko Haram's insurgency has claimed at least 15,000 lives and displaced more than 1.5 million people since 2009.