At least 18 people were killed and 19 seriously wounded in a string of suicide attacks in northeastern Nigeria on Saturday, emergency services said.

In one of three blasts in the town of Gwoza, a female attacker with a baby strapped to her back detonated explosives in the middle of a wedding ceremony, according to a police spokesman, reports AFP.

At least 18 people were killed and 42 others injured in the attacks, according to the Borno State Emergency Management Agency (SEMA).

"So far, 18 deaths comprising children, men, females and pregnant women" have been reported, said Barkindo Saidu, the head of the agency, in a report seen by AFP.

Nineteen "seriously injured" people were taken to the regional capital Maiduguri, while 23 others were awaiting evacuation, Saidu said in the report.

A member of a militia assisting the military in Gwoza said two of his comrades and a soldier were also killed in another attack on a security post, though authorities did not immediately confirm this toll.

Boko Haram militants seized Gwoza in 2014 when the group took over swathes of territory in northern Borno.

The town was taken back by the Nigerian military with help from Chadian forces in 2015 but the group has since continued to launch attacks from mountains near the town.

Boko Haram has carried out raids, killing men and kidnapping women who venture outside the town in search of firewood and acacia fruits.

The violence has killed more than 40,000 people and displaced around two million in Nigeria's northeast.

The conflict has spread to neighbouring Niger, Cameroon and Chad, prompting the formation of a regional military coalition to fight the militants.

Bd pratidin English/Lutful Hoque