At least six people have been killed in a suicide bombing at a college in northern Nigeria’s biggest city, Kano, witnesses say.
The female bomber blew herself up as students queued to check their names on a new admission list, they reported.
This is the fifth attack in Kano since Sunday, at least three of which have been carried out by female bombers.
Militant Islamist group Boko Haram has been widely blamed for the attacks.
It has waged an insurgency in Nigeria since 2009, and appears to have adopted a new tactic by increasingly using female suicide bombers, correspondents say.
The bomber was hidden in the crowd, a witness, Isyaku Adamu, told the AFP news agency.
“It was a huge crowd and people were jostling to go through the lists,” Mr Adamu is quoted as saying.
Who are Boko Haram?
Founded in 2002
Initially focused on opposing Western education – Boko Haram means “Western education is forbidden” in the Hausa language
Launched military operations in 2009 to create Islamic state
Thousands killed, mostly in north-eastern Nigeria – but also attacks on police and UN headquarters in capital, Abuja
Some three million people affected
Declared terrorist group by US in 2013
Who are Boko Haram?
Profile: Boko Haram leader Abubakar Shekau
Why Nigeria has not defeated Boko Haram
The BBC’s Yusuf Ibrahim Yakasai reports from Kano that bodies were strewn around the blast site.
About seven people are said to have been wounded in the explosion.
At least 19 people lost their lives in the series of bombings in Kano in the past week.
In May 2013, Nigeria’s President Goodluck Jonathan imposed a state of emergency in the northern states of Borno, Yobe and Adamawa, vowing the crush the insurgency.
However, the militants have stepped up attacks, killing more than 2,000 civilians this year, according to New York-based Human Rights Watch.
