Jos - An explosion shook an outdoor screening of a soccer match in Jos on Tuesday, wounding several people while fans were watching a Champions league match, witnesses said.
There were no immediate no immediate reports of fatalities from the blast during a match between the British club Chelsea and Barcelona.
Drinking houses, churches and public gatherings are frequent targets for the violent sect Boko Haram, whose members regard those who do not follow its strict brand of Islamist ideology as infidels.
"We were just watching the Chelsea match when there was this huge blast that shook the place, and everyone ran off," said John Azi, who was lightly wounded by the blast in Tudun Wada, on the northern outskirts of the ethnically and religiously mixed city.
"Many people are injured. I didn't see anyone dead," he added.
A spokesman for the military task force keeping security in Jos was not immediately available for comment.
The city has been scarred by ethnic and sectarian conflict for the past decade, and frequent Boko Haram attacks this year,
sometimes targeting churches, seem calculated to inflame tensions.
Boko Haram, which wants to carve an Islamic state out of Africa's most populous country split evenly between Muslims and Christians, used to be confined to Nigeria's northeastern state of Borno, where it began life a decade ago as clerical movement opposed to Western education.
But the sect, or factions of it, has expanded in the past six months across at least 10 states in the north, and they have struck the capital a handful of times.
Jos and other cities on the volatile "Middle Belt" lie on
the delicate fault line between the largely Muslim north and
mostly Christian south that is prone to violence between the two communities.
Two attacks on churches in Jos this year have, however, failed to ignite sustained violence.