An attack that saw two suicide bombers ram their car into a bus station in northern Nigeria has killed at least 22 people and wounded dozens more, police said Tuesday.
The attack on Monday in Kano, the largest city in Nigeria's mainly Muslim north, led to a huge explosion that hit five buses, police spokesman Magaji Majia told AFP.
Witnesses spoke of hearing multiple blasts and said they saw wounded victims in bloodied clothes fleeing the area as authorities cordoned off the scene.
President Goodluck Jonathan condemned the attack and said his government would continue "its unrelenting war against terrorists".
But the government has so far shown little ability to halt violence linked to an insurgency by the Islamist extremist group Boko Haram.
Police spokesman Majia said that sixty-five people were wounded in Monday's attack in Kano.
"Two suicide bombers rammed their Volkswagen Golf car into a luxury bus loaded with passengers about to leave for the south. This led to an explosion that engulfed the bus and four other buses lined up waiting for passengers," he said.
The targeted bus station primarily services passengers heading to the mostly Christian south of Nigeria.
It was also attacked in January of last year in a blast which wounded several people.
Authorities have not said who was behind the bombing and there has been no claim of responsibility, but it was similar to previous attacks by Boko Haram.
Kano has been repeatedly targeted by the group, blamed for killing hundreds in the region since 2009. Its deadliest assault yet occurred in Kano in January 2012, when at least 185 people were killed in coordinated bomb and gun attacks.
Nigeria, Africa's most populous nation and largest oil producer, is roughly divided between a mainly Muslim north and predominately Christian south.
Boko Haram's targets have included symbols of government authority, churches and Muslims it views as collaborating with the government.
A suicide bombing of UN headquarters in Abuja in 2011 killed at least 25 people.
The group has claimed to be fighting for the creation of an Islamic state, though its demands have repeatedly shifted.
It is believed to include various factions with differing aims. One splinter faction, Ansaru, appears to have focused on kidnapping foreigners.
Boko Haram had not claimed any kidnappings until recently, when it said it was behind the abduction of a French family of seven over the border in Cameroon.
The group has demanded the release of prisoners in Cameroon and Nigeria in exchange for freeing the family. Their whereabouts remain unknown, though a recording emerged on Monday in which the father of the family speaks, reading a statement asking the French ambassador to intervene.
Diplomats say Boko Haram members have for years travelled to northern Mali for training with elements of Al-Qaeda's north African affiliate, Al-Qaeda in the Islamic Maghreb.
Many analysts have said poverty and neglect of northern Nigeria, which remains underdeveloped when compared to the oil-rich south, have helped feed the insurgency.
Despite the country's oil reserves, most of Nigeria's population lives on less than $2 per day, with corruption deeply rooted.
The response to the insurgency from Nigeria's military has also worsened the situation, according to rights groups and activists in the region.
Soldiers have been accused of major abuses, including burning homes and killing civilians.
Violence linked to the insurgency in northern and central Nigeria, including killings by the security forces, have left some 3,000 people dead since 2009.