There were 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.

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.

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.

Two attacks on churches in Jos this year have, however, failed to ignite sustained violence.