Kano - A bomb blast killed a 10-year-old boy and wounded 10 others on Sunday, police said, in an area repeatedly targeted by a radical Islamist group.
The explosion went off at about 18:30 in Bauchi city's Tundunwadan Dan-iya area, a neighbourhood known for its cluster of bars and other entertainment spots.
Boko Haram Islamists, responsible for scores of deadly attacks across the north, have previously struck social venues including those that serve alcohol, although no group immediately claimed responsibility for Sunday blast.
"There was an explosion from an improvised explosive device concealed in a wheelbarrow which killed a 10-year-old boy and wounded ten other people," said Mohammed Ladan, police commissioner of Bauchi state, where Bauchi city is the capital
"The wheelbarrow was abandoned by a man disguised as a grocery vendor at a beer garden in the area. No arrest has been made and it is still not clear who was responsible for the explosion," he added.
The Islamists claimed a suicide blast at a church in Bauchi city on 3 June that killed at least 15 people.
The group also carried out a daring prison raid in the state in 2010 that freed scores of its alleged members.
Boko Haram has said it wants to create an Islamic state in Nigeria's mainly Muslim north, although its demands have varied widely as its insurgency has intensified in recent months.
The United States last month designated three of its presumed leaders as global terrorists and Nigerian President Goodluck Jonathan has faced mounting criticism over what some say is his failure to stem the violence.
The radical group, responsible for more than 1 000 deaths since mid-2009, has also consistently carried out attacks on Sundays, although typically targeting Christians worshipping in church.
Boko Haram has also attacked the security services and other symbols of authority in Africa's most populous nation.