KANO (Nigeria) - At least five people have been killed and 10 wounded after a suicide bomber blew himself up outside a leprosy hospital on the outskirts of the north-east Nigerian city of Maiduguri, emergency services said.

The bomber detonated his explosives outside the building at around 5.30pm last Saturday.

"Five people were killed and 10 others injured near the Molai Leprosy Hospital when a male bomber blew himself up," said Mr Mohammed Kanar, regional coordinator for the National Emergency Management Agency.

"The bomber had wanted to get entry into the hospital, but was contemplating how to pass through security checks at the gate when the bomb went off."

He added: "We took the bodies and the injured to the specialist hospital (in Maiduguri)."

Local resident Ibrahim Bulama said the bomber was one of

three men who were dropped off near the hospital by a sport utility vehicle.

"They looked around for a while, obviously trying to sneak into the hospital," Mr Bulama said, adding that the facility was being guarded by civilian vigilantes, who are assisting the military in the fight against Boko Haram Islamist insurgents.

"Suddenly, the explosives on one of them went off. The other two fled in the confusion."

There was no immediate claim of responsibility for the bombing, but Nigeria's Borno state, where the attack took place, has been the hardest hit by the Boko Haram insurgency which has left at least 15,000 people dead.

Boko Haram, which has been fighting to establish a hardline Islamic state in north-east Nigeria since 2009, has intensified its campaign of violence in the last month.

Civilian vigilante Danlami Ajaokuta, who is fighting the Boko Haram, confirmed the hospital explosion and added that there had been a failed suicide attack by two women in Jakarna village, about 40km from Maiduguri, last Saturday afternoon.

In March, three female suicide bombers blew themselves up at a bus stop in the area.

Along with Nigeria, the armies of Chad, Niger and Cameroon have been fighting a joint campaign against Boko Haram for several months, pushing militants out of captured towns and villages.

AGENCE FRANCE-PRESSE