PARIS/ERBIL, Iraq (Reuters) - An Iraqi journalist was killed and three French reporters were wounded after a mine exploded in Mosul, where they were covering an advance by Iraqi forces against Islamic State militants, France 2 television and a diplomatic source said on Monday.

The television network said Iraqi journalist Bakhtiyar Haddad was killed and two reporters, Veronique Robert and Stephane Villeneuve, were wounded and taken to a U.S. military hospital in northern Iraq.

Local Kurdish media had earlier reported the incident saying the French journalists were being treated at the U.S. base in the Iraqi town of Qayyara.

A diplomatic source aware of the incident said two of the journalists were seriously wounded, and a third freelance reporter, was mildly injured.

Islamic State fighters have been defending their remaining stronghold in the Old City of Mosul, moving stealthily along narrow back alleys as U.S.-backed Iraqi forces slowly advance.

The historic district, and a tiny area to its north, are the only parts of the city still under the militants’ control. Mosul used to be the Iraqi capital of the group, also known as ISIS.

France’s foreign ministry declined to comment.