Multiple explosions tore through the central mosque in Nigeria's second-largest city today, killing 35 people, police said.
State Deputy Police Commissioner Sanusi Lemu said 150 others also sustained various degrees of injuries in the blasts in the city Kano.
Hundreds had gathered to listen to a sermon in a region terrorised by attacks from the militant group Boko Haram.
Witnesses said heavy smoke could be seen billowing in the sky from a long distance away. Immediately after the blasts, hundreds of angry youth took to the streets in riots, throwing stones, brandishing sticks and shouting at security officials.
The palace of the Emir of Kano is near the central mosque. Palace officials said the Emir, one of the highest ranking Islamic figures in Nigeria, is currently out of the country.
Boko Haram has not claimed responsibility, but the attack bears the hallmarks of the militant group which has carried out numerous such attacks in northern Nigeria, including in Kano. In September, two suicide bombers killed at least 15 students at a government college and in July, five suicide bombings were carried out over the course of a week. More than 1,500 have been killed this year in the insurgency.
Nigerian President Goodluck Ebele Jonathan condemned the attack and reiterated the government's determination to "continue to take every step to put an end to the reprehensible acts of all groups and persons involved in acts of terrorism".
He called on all Nigerians "to remain united to confront the common enemy" by being vigilant and cooperating with security agencies.
He also called on relief agencies and medical staff to "deploy every possible effort to assist the injured" and urged the public to donate blood to the hospitals where they are treated.
Meanwhile, a police anti-bomb squad defused six bombs planted near a mosque and a market in Maiduguri, according to Borno state police spokesman Gideon Jubrin.
Fears are running high in Maiduguri after two female suicide bombers detonated explosives on Tuesday at a commercial center. At least 70 people were killed.