DAMATURU, Nigeria (Reuters) - A young female suicide bomber killed at least 10 people and injured more than 20 in an attack on Tuesday in a market in northeast Nigeria, several witnesses said, the second such attack within 24 hours.
The attack bore the hallmarks of militant Islamist group Boko Haram, which is stepping up suicide attacks in towns and cities after losing most of an area the size of Belgium in the northeast since the start of the year.
President Muhammadu Buhari, who has vowed to crush the insurgency, on Tuesday accepted an invitation to visit President Paul Biya in neighboring Cameroon as part of efforts to intensify the region's joint fight against Boko Haram.
The suicide bomber struck at about 11 a.m. (1000 GMT) at a market in Gujba, a town that was reclaimed from the Islamist group earlier this year as Nigeria's military went on the offensive with support from Chad, Niger and Cameroon.
The blast came a day after another female suicide bomber hit a market in Maiduguri in an attack that bore the hallmarks of Boko Haram, which has killed thousands during its six-year insurgency in northeast Nigeria.
"I saw the suicide bomber, a small girl of not more than 12 years. I counted over 10 people that were dead," said Hussani Ibrahim, a driver, who added that he helped transport 23 injured to a hospital in Damaturu.
Buhari has held talks in the last few weeks with counterparts in neighboring countries to set up a regional force to tackle the insurgency. His spokesman Femi Adesina said Cameroon's president had made assurances of "brotherly commitment" to working with Nigeria to end the insurgency.
Nigeria's president also promised on Tuesday to provide "special assistance" for the three northeastern states that have been worst hit by Boko Haram, without giving further details.
Reporting by Joe Hemba; Writing by Alexis Akwagyiram; Editing by David Clarke