The bombings, which took place on Wednesday night in Waza near the Nigerian border, targeted a busy area in the market town, the sources said, adding that some of the injured were in serious condition.

"At present we have a provisional toll of 17 dead (including the suicide bombers) and 45 wounded," Doctors without Borders (MSF) in Cameroon told AFP when contacted by phone from Yaounde.

The bombers struck an area with "restaurants, telephone cabins and kiosks" at around 9:30 pm (2130 GMT), a local official said.

"The town has been sealed. Nobody can enter and nobody can leave," the source said, adding: "The condition of some of the injured is quite serious."

Though Boko Haram originated in Nigeria, the Islamic State-affiliated group has carried out frequent attacks in Cameroon, Chad and Niger, prompting the formation of a regional force to fight back.

Cameroon's Far North region, which borders Nigeria, has seen a resurgence in attacks blamed on Boko Haram after months of relative calm.