Two Chinese nationals working on a road project in Central African Republic were kidnapped in an attack three weeks ago on a border post along the Cameroonian frontier, a police source said Monday.

Gunmen abducted the Chinese after opening fire on a toll stop at the Garoua-Boulai border post in eastern Cameroon on the night of September 23-24, said a source in Central African Republic's gendarmerie.

At the time of the attack, Cameroon's state broadcaster reported that "armed rebels" had carried out the raid, killing two people including the head of the border post.

An attacker was later found deadsome 20 kilometres (12 miles) away along with the vehicle used in the raid.

The two Chinese nationals, who were working on a road linking the Centrafrican town of Bouar to the border crossing, were kidnapped as the attackers fled, the police source said.

The source added that Central African Republic's deputy parliament speaker, a cabinet minister and the army chief of staff had visited the western region at the weekend to investigate the attack.

No group has claimed responsibility for the raid, and police have not identified any suspects.

Central African Republic's northwest is a haven for numerous armed groups, carjackers and poachers.