LAGOS: A bomb blast and gunfire shook an area around an Islamic school in northern Nigeria on Sunday, leaving two of the alleged attackers dead and others wounded, emergency officials said.
It was not immediately clear who was behind the blast, but Islamist extremist group Boko Haram has been blamed for hundreds of deaths as part of its insurgency in northern and central Nigeria.
The boarding school is run by Salafist cleric Awwal Adam Albani, known for his outspoken criticism of Boko Haram.
Details of the blast in the northern city of Zaria were sketchy, with initial reports that the explosion had occurred inside the school followed by information that it had only occurred near it.
"It's close to a boarding school called Albani," National Emergency Management Agency spokesman Yushau Shuaib told AFP.
"Two suspects were killed. The innocent victims that were injured were taken to hospital."
Shuaib said it appeared the school was the target based on initial information that the attackers had sent a warning asking students to evacuate. He was not immediately able to provide further details.
Attackers and security forces appeared to exchange gunfire after the explosion, leaving the two suspects dead, he said.
Another relief official said there had also been an exchange of fire between security forces and gunmen Saturday night. He said Sunday morning's explosion was the result of an improvised explosive device.
Nigeria's north has been hit by scores of bombings and shootings blamed on Boko Haram, whose insurgency is blamed for more than 1,400 deaths since 2010. A string of attacks have also hit the country's centre.
In June, two churches were attacked in Zaria and one in the city of Kaduna, both cities located in Kaduna state.
The church attacks left at least 16 people dead and sparked reprisals by Christian mobs who burned mosques and targeted Muslims, killing dozens. Boko Haram claimed responsibility for the attacks.
Nigeria is Africa's most populous nation and largest oil producer, roughly divided between a mainly Muslim north and predominately Christian south.
Boko Haram has claimed to be fighting for the creation of an Islamic state in Nigeria's north, though its demands have repeatedly shifted.
It is believed to have a number of factions with varying aims, in addition to imitators and criminal groups who carry out violence under the guise of the group.