Two Rafale fighter jets have collided in mid-air before crashing to the ground in northeastern France, civil and military authorities said.

A search for one of the crews was under way.

The two jets were from the Saint-Dizier air base, an air force spokesman in Paris said on Wednesday.

One of the pilots ejected himself, he said.

But an instructor and a student pilot from the second aircraft were still missing.

"We are still looking for the second crew," the spokesman said.

The accident occurred in Colombey-les-Belles, a town in northeastern France, according to the prefecture.