Boko Haram Islamists on Friday seized control of a town in the far north of Cameroon which lies on the border with Nigeria, security and regional sources said.

“They now control Kerawa,” a security source told AFP on condition of anonymity, referring to the Nigerian Islamist group.

The information was confirmed by another source close to the regional authorities, who said an unspecified number of civilians had been killed in the assault.

“Boko Haram has controlled Kerawa since Friday morning,” the source said adding the Cameroonian army had sent in reinforcements.

It was not immediately clear whether troops had engaged in any fighting with the Islamists.

The security source “several people” killed inside the mosques in the town on Thursday, quoting an unconfirmed report that 11 people had died.

Kerawa, which has 50,000 inhabitants, is located in the Kolofata district that is regularly targeted by Boko Haram.

There is a military camp inside the town, which was last hit by a double suicide bombing on September 3, which claimed at least 30 lives.

Cameroon, Chad and Niger have formed a military alliance with Nigeria and Benin to battle the extremists, who this year declared allegiance to the Islamic State.

The Islamists' grip on the region has suffered as a result of offensives launched by local armies.

But the group maintains strongholds in areas that are difficult to access, such as the Sambisa forest, the Mandara mountains and the numerous islands of Lake Chad.

Also on Friday, at least 28 people were killed in a suicide bombing at a mosque in Maiduguri in northeast Nigeria.

Since 2009, the insurgency has claimed at least 17,000 lives.

•Photo shows Boko Haram insurgents.

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