Suicide bomb attacks in Maiduguri.
Bomb damage in a market area after an explosion in Maiduguri, northeastern Nigeria.Reuters

The city of Maiduguri in Nigeria was hit by a series of suicide bomb attacks over a four hour period today. Locations targetted included a crowded fish market and a bus station, according to Police Commissioner Clement Adoda.

A fifth explosion from a car bomb at a military checkpoint 50km outside the city injured a soldier and two members of a civilian self-defence unit. The bomber was attempting to reach Maiduguri, a police officer told AP.

The most fatalities in a single attack occurred at an explosion at a tricycle taxi stand at the entrance to Baga fish market, where 18 were killed, according to police.

"I saw many dead bodies lying on the ground, many dead, and several others badly injured," said fish seller Idi Idrisa.

An hour later, a second blast shook the Post Office shopping area near the market, according to Baban Musa, who said there were many casualties.

A third blast went off at Monday Market, the biggest in Maiduguri, while a fourth caused devastation at the Borno Express bus station.

No one immediately claimed responsibility for the attacks, but they bear similarities to the Boko Haram Islamic extremist group. Maiduguri is the birthplace of Boko Haram and the group have made it the target for many bombings since they were driven from their base there after a military state of emergency was declared in May 2013.

Maiduguri is the birthplace of Boko Haram and the group have made it the target for many bombings, since they were driven from their base there after a military state of emergency was declared in May 2013.

Boko Haram has increased suicide bombings and village attacks in recent weeks as forces from Nigeria and Chad have driven the insurgents from a score of towns along Nigeria's border with Cameroon.

The African Union has endorsed the creation of a regional force of up to 10,000 men to join the fight against the Nigerian Islamist group Boko Haram, diplomats said on Friday.

The force, the idea for which was adopted at an African Union summit in January, will be based in Chad's capital N'Djamena, the pan-African bloc's Peace and Security Council said, according to a News24 report.

This is the latest drive "to prevent the spread of Boko Haram activities and other terrorist groups" and "eradicate their presence", said a spokesman for the African Union.