Kano (Nigeria) (AFP) - At least seven people were killed in a suicide bomb attack near a camp for those displaced by the Boko Haram conflict in northeast Nigeria, the army said on Thursday.

The attack happened early Wednesday in Banki, a town on the border with Cameroon some 130 kilometres (80 miles) southeast of the Borno state capital, Maiduguri.

"Seven people lost their lives. There were two suicide bombers," both women, army spokesman Colonel Sani Usman told AFP.

News of the attack was slow to emerge because of the poor to non-existent telecommunications in the remote area.

Usman said one of the women failed to detonate her explosives and was arrested, despite being injured but a civilian vigilante said the second bomber died of her wounds on her way to hospital.

"Two female suicide bombers came by a checkpoint manned by CJTF (civilian joint task force) and the military at about 6:30 am (0530 GMT) yesterday (Wednesday)," the vigilante said.

"They successively detonated their explosives. One of them died instantly while the second one was badly injured.

"She died on the way to Maiduguri because she was evacuated along with the wounded. Seven people were killed including two women and their infants.

"A vigilante and two residents were also killed. Nine people were injured and we brought them to Maiduguri for medical attention."

Boko Haram has carried out suicide bombings often using women and girls as part of its armed campaign to establish an Islamic state in northern Nigeria.

Mosques, crowded markets, bus stations and military checkpoints have been frequent targets.

But in February, two female suicide bombers killed at least 58 at camp for those made homeless by the insurgency in Dikwa, some 90 kilometres from Maiduguri.

That attack raised security fears about the safety of internally displaced people (IDPs), whom the government is encouraging to return home.

Suicide bombers also tried to get inside one of the biggest IDP camps near Maiduguri in January after a Boko Haram attack on a nearby village that killed at least 85.