An explosion in a brothel in the northeastern Nigerian city of Bauchi has killed 11 people and wounded 28, police have said.
Suspicion for the blast immediately fell on the Boko Haram group, which has in the past few months targeted several cities across north and central Nigeria with a bombing campaign, killing hundreds of people.
Bauchi state police spokesman Haruna Mohammed said a person had been arrested on Saturday in connection with the blast. He gave no further details.
Boko Haram's targets often include places it considers sinful according to its austere brand of Sunni Islam, such as bars, schools or churches.
Boko Haram fighters say they are fighting to carve an Islamic state out of religiously-mixed Nigeria, Africa's most populous country, biggest economy and leading energy producer.
Bauchi state lies on Nigeria's volatile "Middle Belt", where its largely Christian south and Muslim north meet.
The blast in Bauchi came days after a bomb in an upmarket shopping district of the capital Abuja killed 21 people. It was the third attack on the capital in the past three months.
In Nigeria's second-biggest city of Kano, the relic of a medieval Islamic caliphate, police acting on a tip-off said they had found and defused a bomb consisting of 13 cylinders of explosives next to the Jumat Praying Ground late on Friday.
"The high-grade explosives were loaded into a rickety red (Toyota) Starlet," Kano police commissioner Alhaji Adenrele Shinaba told journalists at a news conference.
"They were primed to explode on worshippers."
Boko Haram often attacks mosques as well as churches, especially if they are seen as too moderate.
The group has killed many thousands since launching an uprising in 2009, and see all those who do not share their views as enemies.