Maiduguri - More than 45 people died Tuesday in twin bomb blasts, including one by a female suicide bomber, at a packed market in the Nigerian city of Maiduguri.
The explosions in the Borno state capital targeted the same Monday Market area where at least 15 people died July 1 in blast blamed on the Boko Haram militant group.
Tuesday's attack came after the militants seized control of another town in Nigeria's restive northeast.
Health worker Dogara Shehu said he counted more than "45 people killed, some of them completely decapitated" in the Maiduguri blasts in an account supported by another witness.
An official with Nigeria's National Emergency Management Agency (NEMA) confirmed that "many people have been killed" but did not have an official death toll.
Also read: Several killed as female bombers strike in Maiduguri
One senior police officer, who requested anonymity, described the explosion, which happened at about 11:00 am (1000 GMT), as a "powerful bomb", which was felt across the city.
Market trader Usman Babaji told AFP the explosives were hidden in a motorised, three-wheeled rickshaw, which are popular throughout the country.
A second explosion followed moments later as people rushed to the scene of the first bombing to help the injured, witnesses said.
Abubakar Bello, who sells chickens near the scene, said the woman was carrying explosives in a wrapper on her back, in the same way that babies are carried.
"She manoeuvered her way to the scene of the earlier explosion," he said in an account supported by three others.
"I think it was a deliberate plan to inflict much pain on unsuspecting people because the second explosion went off after many people gathered at the scene of the first one."Boko Haram suspected
Boko Haram will likely be blamed for the blasts, given that it has attacked Maiduguri dozens of times during its five-year fight to create a hardline Islamist state in northern Nigeria.
The Islamist group was founded in Maiduguri more than a decade ago and the city was once the epicentre of the conflict until its fighters were pushed out into more rural parts of the northeast.
Since May 2013, when a state of emergency was imposed in Borno and two neighbouring states, violence has increased in the countryside, killing thousands and forcing many more to flee.
Boko Haram had earlier taken over the town of Damasak, in the far north of Borno near the border with neighbouring Niger, starting their assault with an attack on the market there early Monday.
Maina Ma'aji Lawan, who represents northern Borno state in Nigeria's Senate, said soldiers and hundreds of residents fled when the heavily armed militants opened fire on traders.
"There is not a single male in Damasak. Boko Haram is in control because all males and soldiers have fled. No one expects women to fight them," Lawan told AFP by telephone from Abuja.
A senior security source in Maiduguri and a senior local government official both corroborated Lawan's account, although it was still unclear how many were killed in the attack.Maiduguri targeted
Boko Haram's territorial gains are a change in strategy from its previous trademark of deadly hit-and-run raids or high-profile strikes against government, police or military targets.
The group's seizure of towns has raised fears about a potential loss of government control in the region.
Many in recent weeks have warned that violence would return to Maiduguri and some have voiced concern that the Islamists might try to capture the key city.
Losing Maiduguri would be a huge blow for Nigeria's territorial integrity, but the military dismissed the warnings as alarmist.
Despite claims that they have since retaken a number of towns seized by the militants, soldiers have largely been unable to halt Boko Haram attacks throughout the northeast.
Lawan said he feared that Damasak may suffer the same fate as Malam Fatori, a nearby fishing hub which was overrun earlier this month.
"When Boko Haram seized Malam Fatori recently, the military kept giving us assurances that they were going to deploy and take it back," the senator added.
"But the town is still in the hands of the insurgents and not a single soldier has been deployed to fight them. Our concern is Damasak may not be any different."