Separate attacks claim at least 29 lives, after suicide bombers left more than 20 dead in neighbouring Cameroon.
At least 19 people have been killed and 47 others injured when explosives carried by a girl, aged about 10, detonated in a crowded market in the Nigerian city of Damaturu, police have said.
No one claimed responsibility for Sunday’s explosion but the latest attack bears the hallmarks of the armed group Boko Haram.
Police spokesman Toyin Gbadegesin told the Reuters news agency that the bomber, “a female of about 10 years old capitalised on the crowded entrance of the market where screening was being conducted and detonated the device”.
At least two other females were killed in the attack.
Hundreds of people have been killed in bombings and shootings across northern Nigeria since Muhammadu Buhari was inaugurated as president on May 29.
He has made a number of changes aimed at tackling the insurgency, including replacing his defence chiefs.
Buhari moved Nigeria’s defence command centre to Maiduguri, the birthplace of Boko Haram, and has worked with counterparts in neighbouring countries to set up a multinational force with headquarters in Chad’s capital, N’Djamena.
Sunday’s attack in Damaturu occurred six days after a suicide bomber killed three policemen at a checkpoint on the city’s outskirts.
Earlier this month at least nine people were killed in the city by a female suicide bomber as worshippers gathered to mark the Muslim holiday Eid al-Fitr.
Boko Haram, which controlled large expanses of territory at the end of 2014, have been pushed out of most of that territory by Nigerian troops in the last few months, with military help from neighbouring Chad, Niger, and Cameroon.
Since then, Boko Haram, which wants to form an Islamic state, has carried out attacks in Nigeria’s north as well as neighbouring countries.
On Saturday, at least 19 people were killed in a suicide bombing in the northern Cameroonian town of Maroua.