At least 19 people have been killed following an attack by three suicide bombers in the northeast Nigerian city of Maiduguri, capital of the state worst hit by the Boko Haram insurgency, its police commissioner has said.

The police commissioner for Borno state, said the attack took place at a fish market around 20km from the centre of Maiduguri at about 8pm local time yesterday.

"The three suicide bombers were killed and 19 other persons died," Commissioner Damian Chukwu said.

An official from the Civillian Joint Task force said there were 19 people dead and over 70 people injured in the blast.

Suicide bombings have continued despite repeated assertions by the government and the military since 2016 to have defeated the Boko Haram insurgency, which aims to create an Islamic state in Nigeria's northeast.

President Muhammadu Buhari took office in 2015 with a promise to improve security for ordinary Nigerians.

But in addition to the jihadist insurgency, communal violence has plagued swathes of the country in the last few months, including a clash on Thursday that killed 18.

Nobody has claimed responsibility for the attack but the use of suicide bombers in crowded areas is a hallmark of the Islamist militant group, which has killed more than 20,000 people since 2009 and forced over two million to flee their homes.