Search and rescue teams are scouring the mountainous region along France’s eastern border after a French Air Force Mirage 2000-D fighter with two crew members on board went missing Wednesday morning. The fighter reportedly vanished from radar screens at approximately 11 a.m. local time shortly after taking off from the Nancy-Ochey Air Base in Ochey, France.

“We’re looking for this plane which disappeared from the radars” in the Jura, the prefecture administration said.

The fighter was last seen on radar between the regions of Doubs and Jura, not far from the Swiss border. Concerns about the crew have been bolstered by reports from local residents who claim to have heard a large explosion Wednesday morning, though some have suggested the sound may have been a sonic boom produced by the fighter going supersonic. The search effort has been hindered thus far by heavy snowfall in the region, limiting visibility for air crews looking for signs of a wreckage in the mountains.

Russian state-owned news outlet RT has reported that debris has been spotted in the mountains around where the Mirage 2000-D may have gone down, but thus far, French authorities have not confirmed their claims. French newspaper L’Est Republicain has also reported that a parachute and map were both found by local authorities, adding that the crew was comprised of one man and one woman, but again, thus far French officials have not corroborated these statements.

Military explosives ordnance disposal and chemical intervention units are reportedly on hand to assist in cleanup efforts, though it remains unclear if the Mirage 2000-D was carrying any live ordnance when it disappeared.

Feature image courtesy of U.S. AFRICOM