MAIDUGURI, Nigeria (AFP) - At least 19 people were killed on Saturday when a young girl, thought to be aged about 10, blew herself up at a crowded market in the restive north-east Nigerian city of Maiduguri.
The powerful explosion rocked the city's Monday Market at about 12.40pm when it was packed with shoppers and traders.
The same market was hit twice by female suicide bombers late last year.
The latest atrocity came a week after a major Boko Haram attack on the fishing town of Baga in northern Borno State, which is believed to be the worst in the bloody six-year insurgency.
The town and at least 16 nearby settlements in and around Lake Chad were burnt to the ground and at least 20,000 people forced to flee their homes.
"For 5km, I kept stepping on dead bodies until I reached Malam Karanti village, which was also deserted and burnt," one survivor, fisherman Yanaye Grema, said.
But there was no independent corroboration of huge numbers of dead cited locally.
In Maiduguri, there was no immediate claim of responsibility but Boko Haram has increasingly used women and young girls as human bombs in their deadly campaign for a hardline Islamic state.
Ashiru Mustapha, a civilian vigilante, said the explosives detonated as the girl was being searched at the entrance to the market.
"The girl was about 10 years old and I doubt if she actually knew what was strapped to her body," he told AFP.
"In fact, she was searched at the entrance of the market and the metal detector indicated that she was carrying something.
"But sadly, the explosion went off before she was isolated."
Witness Abubakar Bakura said: "The blast split the suicide bomber into two and flung one part across the road.
"Among the dead are two vigilantes who were searching the girl. I am pretty sure the bomb was remotely controlled."
A Red Cross official, who declined to be named, warned: "Many people sustained life-threatening injuries."
Borno State police spokesman Gideon Jubrin told reporters 19 people were killed and 18 others were injured but warned that the death toll could rise.
The market in the Borno State capital was cordoned off as health officials began the grim task of sifting through the wreckage and collecting body parts.
An attack at the market on Dec 1 killed more than 10 people, and the previous week more than 45 people lost their lives in an attack there.
On July 1, at least 15 people were killed in another suicide attack blamed on the militants.
Boko Haram launched its first female suicide attack in June last year in the northern state of Gombe and there have been a spate of bombings since, including four in a week in the city of Kano in July.
The same month a 10-year-old girl was found in Katsina state wearing a suicide vest, prompting fears that young girls were being forced into becoming human bombs rather than through ideological motivation.
Forced conscription of young men and boys by Boko Haram has been well-documented.
Last July, three women said to be "female recruiters" for Boko Haram were arrested.
An alleged trainer of women bombers was also detained in Kano in August with up to 16 "trainees".
Boko Haram is now said to be in control of all three borders of Borno state with Niger, Chad and Cameroon, as well as dozens of towns and villages in Borno and the neighbouring states of Yobe and Adamawa.
Security analysts said the Baga attack was likely against civilian vigilantes assisting the military.
On Friday, militants fought running battles with troops in the Yobe state capital, Damaturu.
The attack was said to be a reprisal for an offensive by civilian vigilantes and local hunters against a Boko Haram enclave in southern Yobe on Tuesday.