Kano - Two female suicide bombers killed at least four people at a busy market in northern Nigeria's largest city Kano on Wednesday, less than two weeks after a horrific attack at the city's central mosque.
Boko Haram has been accused of deploying a wave of female bombers in recent months, including in Kano, and blame for the latest violence will likely fall on the insurgents.
Kano state police commissioner Adenrele Shinaba said the blast at the Kantin Kwari market in Kano city was "a twin suicide bombing carried out by two young girls in hijab".
"They came by the market and asked to be directed to a public convenience. The bombs detonated, killing them and four others," he told AFP. At least seven others were injured, he added.
The leader of the market traders union, Abdullahi Abubakar, said the blasts hit a parking area rather than the main market.
Also read: Four killed in Kano double suicide bomb attack
He estimated that the attackers were in their late teens and said they were accompanied by a man who disappeared after the girls blew themselves up.
Blood stained the walls and floors of affected buildings following the blasts. Angry youths converged on the area and were kept at bay by police and soldiers, an AFP correspondent said.
The bombers' remains were then taken away.Key city targeted
Kano, the key city in the mainly Muslim north, has been among the places hardest hit by Boko Haram's five-year uprising aimed at creating a caliphate in the region.
A November 29 attack on worshippers attending Friday prayers at the central mosque killed at least 120 people and injured 270 others, the second deadliest attack in the ancient city.
Boko Haram gunmen rampaged across Kano in January 2012, killing at least 185 people.
Last month's mosque bombing apparently targeted the influential Emir of Kano, Muhammad Sanusi II, who had previously called on citizens to take up arms against Boko Haram.
Sanusi was not at the mosque at the time of the attack but analysts said the Islamists may have been trying to send him a message after several previous assassination attempts against other Islamic leaders who spoke out against extremism.
Kano was attacked by female bombers four times in one week in July, while several similar attacks have hit a series of northern cities in recent weeks, including the Borno state capital Maiduguri, where Boko Haram was founded more than a decade ago.Political week
As rescue workers sifted through the damage of the north's latest bombing, political heavyweights were gathering in the capital Abuja and the commercial hub of Lagos in the south for party conventions ahead of February 14 polls.
President Goodluck Jonathan is expected to be nominated without contest by the ruling People's Democratic Party in Abuja.
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While he is all but certain to be on the ballot, some believe the deteriorating security crisis in the north could complicate his re-election prospects.
Northerners hit by Boko Haram violence have voiced increasing frustration with Jonathan's failure to stem the bloodshed and questioned the military's competence in responding to the insurgency.
In Lagos, the opposition All Progressives Congress was set to nominate a northern Muslim to challenge Jonathan.
Former military dictator Muhammadu Buhari and ex-vice-president Atiku Abubakar were seen as frontrunners for the nomination.