At least 18 soldiers in western Niger were killed and four others were missing after suspected Islamist militants blew up two cars and fired on a military camp, the army said on Tuesday.

The raid occurred on Monday afternoon near the town of Inates, close to the border with Mali, where militants are active, and in the same region where an ambush by ISIL's West African branch killed 28 soldiers in May.

Niger hosts the African Union summit from July 6-9 less than 200 km (125 miles) away in the capital Niamey. In the run-up, the European Union has been training Nigerien forces to respond to militant attacks.

An army statement said the attack began with the explosion of two car bombs before additional assailants opened fire from motorcycles.

The army's "partners" then responded with air strikes to force them across the border into Mali.

(Cover image via VCG: Niger's soldiers patrol near Bosso on June 17, 2016 following attacks by Boko Haram fighters in the region.)