Kano (Nigeria) (AFP) - A suspected Boko Haram bomber was killed and a security guard was wounded Saturday in a botched suicide attack on a crowded market in northeast Nigeria's Borno state, vigilantes told AFP.

The attacker detonated his explosives at the entrance to the weekly market in Rumurigo village in Askira Uba district when vigilantes insisted on searching him, they said.

"The bomber arrived at the entrance of the market around 11:00 am and our men insisted on screening him as with every person going into the market but he just blew himself up, injuring a vigilante on the arm," one of the vigilantes, Markus Yohana, told AFP.

Bitrus Damina, a local man who was at the market at the time, confirmed the incident.

"There was an explosion around 11:05 am outside the market which caused panic and (a) stampede and we later learnt it was a suicide bomber that blew himself up at the entrance after he refused to be searched," he said.

One vigilante was injured, he said.

The Nigerian army said the attack "was thwarted by a gallant vigilante group member."

"In the process of interrogation, the suspected terrorist blew himself off and died on the spot," spokesman Colonel Sani Kukasheka Usman said.

The wounded vigilante was being treated in hospital, he added.

Last month, Boko Haram gunmen attacked the nearby village of Dille on motorbike, killing three vigilantes before soldiers pursued the assailants into the bush, killing 11 of them.

The Nigerian air force said in a statement Saturday it had launched air strikes on Boko Haram's Sambisa Forest stronghold "to incapacitate and further degrade the fighting spirit" of the Islamists.

Boko Haram is seeking to carve out a hardline Islamic state in northeast Nigeria. Its insurgency has led to the deaths of at least 15,000 people since 2009.

A four-nation military offensive gathering Nigeria and its neighbours has pushed Boko Haram out of captured territory since February.

In response, the group has reverted to its previous tactics of suicide and bomb attacks against so-called soft targets such as markets and transport hubs.