A 10-year-old boy has died after a rocket was fired at a school in the Nigerian city of Jos but missed and hit a nearby building, officials say.
The school authorities say the boy was not a pupil at the large co-educational institution owned by the city's Muslim community.
The BBC's Ishaq Khalid in Jos says the students were sitting their exams at the time of the blast.
Jos has witnessed years of inter-ethnic and religious violence.
The city is the capital of Plateau state, which lies on the fault line between Nigeria's mainly Muslim north and Christian and animist south.
Villagers agree deal
Our reporter says it is not the first time that the Nurul Islam junior and senior school has experienced trouble.
Several weeks ago some people were arrested and a bomb defused in the area surrounding the school, he says.
Thousands of people have been killed in years of attacks between the rival communities in Plateau state.
The militant Islamist group Boko Haram, which is fighting to overthrow the government and create an Islamic state, has also been behind various attacks over the past 18 months in Jos, mainly on churches.
Last week it said it had killed two politicians who were attending a funeral for people who died during communal violence in Plateau state.
Some 100 people were killed in attacks on villages inhabited by Christian Berom groups this month.
On Monday, the security forces agreed a deal with the Muslim Fulani community that the residents of five villages near Jos would temporarily move out to allow a 48-hour operation to flush out insurgents believed to be behind recent violence.
Analysts say the long-standing rivalries between communities stem from a dispute about who are the area's rightful inhabitants, tensions often whipped up by local politicians.
President Goodluck Jonathan has also accused Boko Haram of trying to stir up violence between Christian and Muslim groups.