Police in southern Nigeria say assailants have thrown a bomb into an Arabic school, wounding seven people days after a string of deadly church bombings across the country.
Authorities in Delta state say the homemade bomb went off after it was thrown from a car late Tuesday. Six children were among the wounded.
The attack follows a string of four coordinated bombings Sunday that killed at least 39 people.
The radical Muslim sect Boko Haram claimed responsibility for the Christmas Day attacks.
Christians in northern Nigeria have warned that increased violence could lead to a religious war.
In other violence, gunmen shot and killed a young girl and her parents late Tuesday in a Christian-dominated village near the central city of Jos. Officials suspect the attack was carried out by Muslim tribesmen.
Jos is the site of frequent clashes between Christians and Muslims.
Boko Haram, whose name means "Western education in sinful" in the Hausa language, wants to establish a strict Islamic state in Nigeria. It does not recognize the government or the country's constitution.
The country of 150 million is about evenly divided between Muslims, who mostly live in the north, and Christians who dominate in the south.
Hundreds of others have died this year in bombings and shootings blamed on Boko Haram.