Brothel blast in northeast Nigeria kills 11
* Police say cause of brothel blast unknown
* Second bomb found next to mosque defused by police in Kano
* Suspicion likely to fall on Islamist militants Boko Haram
* Bomb in Abuja shopping district on Wednesday killed 21
An explosion overnight in a brothel in the northeastern Nigerian city of Bauchi killed 10 people, police said on Saturday, with suspicion likely to fall on Islamist militant group Boko Haram.
The statement sent by text message said the cause of the blast was unknown. Boko Haram has targeted several cities across north and central Nigeria in a bombing campaign in the past few months, killing hundreds of people.
A military operation in the north east has so far failed to quell the rebels and has triggered a string of reprisal attacks on officials and civilians. Boko Haram's targets often include places it considers sinful according to its austere brand of Sunni Islam, like bars or churches.
The insurgents 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 police spokesman Haruna Mohammed said 14 people were rushed to hospital after the explosion in the People's Hotel brothel, at the Bayangari area of Bauchi metropolis.
"The entire building has been cordoned off and the scene secured. No arrest has been made but an investigation has commenced to ascertain the cause," he said.
Bauchi state, like neighbouring Jos, straddles Nigeria's volatile "Middle Belt", where its largely Christian south and Muslim north meet. The region has been less frequently attacked by Boko Haram than its heartland in the remote northeast.
But the militants seem keen to demonstrate their ability to extend their reach beyond the region of military operations against them centred around Borno state. A bomb in an upmarket shopping district of the capital Abuja killed 21 people on Wednesday, the third attack on the capital in 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 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 insurgents have killed many thousands since launching an uprising in 2009, and several hundred in the past two months as they have stepped up a bloody campaign against civilians in the northeast. Boko Haram sees all who do not share its views as enemies.
President Goodluck Jonathan said on Friday Nigeria had entered one of the darkest phases of its history, visiting the scene of Wednesday's Abuja bomb blast.
The kidnapping of more than 200 school girls by the insurgents from the village of Chibok in April made world headlines and elicited offers of help from Western powers to get them freed, although global public interest is now waning.
The United States reduced its surveillance flights to help find the girls after building a body of intelligence and after other states ramped up support, a U.S. official said on Friday.
Jonathan's administration has been bruised by criticism of its failure to contain the insurgency or protect civilians, especially in the volatile northeast.
"I have had to remain quiet about the continuing efforts to find the girls kidnapped in April," Jonathan wrote in the Washington Post on Thursday, saying he was concerned his critics would equate his silence with "inaction or even weakness".
"We have not stopped and will not stop until the girls are returned home," he wrote.