Six people have been arrested over the kidnapping of 10 Chinese workers in northern Cameroon, two officials have told AFP, a raid that has been blamed on the Nigerian Islamist group Boko Haram.

The kidnapping, on May 17, took place in Waza, a town near the border with Nigeria, when the workers' construction camp was raided in the middle of the night. A Cameroonian soldier was also killed in the attack.

"Six people have been taken in for questioning in Waza" as part of the investigation, a source close to the security services said on condition of anonymity.

Three Nigerians living in Waza were among those taken in for questioning, the same source said, adding that the latest arrest took place on Monday.

A local official confirmed the arrests to AFP.

"A number of people have been arrested during the course of the investigation. It is a military operation," the source said, without giving further details.

The kidnapping is believed to be the latest raid by Boko Haram who have been known to take advantage of a porous border to slip from their stronghold in northeastern Nigeria into Cameroon.

The authorities in Yaounde have been quick to blame the Islamist group, which has been waging a bloody insurgency in Nigeria since 2009, although the group has not claimed responsibility for the attack.

Cameroon shares a border of more than 2,000 kilometres (1,200 miles) with Nigeria, and the country's president has committed to sending 3,000 troops and police to the troubled border northern region over the next few weeks. The first troops have already started to arrive.

At the weekend, two Italian priests and a Canadian nun seized by suspected Boko Haram gunmen near the border were released after two months being held hostage.