Russian aviation authorities said on Sunday a Russian-registered plane with six people thought to be on board disappeared from radar screens over Afghanistan the previous night, after local Afghan police said they had received reports of a crash.

The plane was a charter ambulance flight travelling from Thailand’s Utapao Airport in Pattaya to Moscow via India and Uzbekistan on a French-made Dassault Aviation Falcon 10 jet manufactured in 1978, Russian aviation authorities said in a statement.

About 25 minutes before the plane vanished from radar screens, the pilot warned that fuel was running low and that the plane would try to land at an airport in Tajikistan, Russian news outlet SHOT reported, citing an unnamed source.

The pilot then reported that one engine had stopped, and then that the second one had also stopped, SHOT reported.

Reuters could not immediately confirm the details shared by SHOT.

India’s civil aviation authority said the plane was not a scheduled commercial flight or an Indian chartered aircraft and that it awaited more details.

The flight was carrying out a private medical evacuation from Thailand’s Pattaya, a popular tourist destination for Russians, to Moscow, Russian state-run TASS news agency reported, citing the Russian embassy in Bangkok.

“On board was a bedridden patient in serious condition, a Russian citizen, who was transported from one of the hospitals in Pattaya to Russia,” the RIA news agency reported, citing a source at Thailand’s Utapao International Airport.

“She was accompanied by her husband, a private entrepreneur, also a Russian citizen, who paid for the flight.”

Several Russian media outlets said the passengers were a couple from Volgodonsk in southern Russia.

A manifest list for the plane, published by the SHOT news outlet, appeared to show the crew were Russian nationals, too.

Russia’s Investigative Committee said it had opened a criminal case to determine if safety rules had been violated.

The plane’s reported owner, a small Russian firm called Athletic Group LLC, did not immediately respond to a request for comment.

The Taliban-run Afghan aviation ministry said in a statement on X that the plane’s planned route did not include passing through Afghanistan’s air space and that “probably due to technical issues” the plane had diverted from its planned route.

The statement said a ministry technical team was investigating the matter.

Police in northern Afghanistan had received reports of a plane crash in Badakhshan province, a provincial police spokesperson said on Sunday.

Zabihullah Amiri, a spokesperson for Badakhshan’s provincial government, told Reuters a team had been sent to the location of the crash, but it was a remote area more than 200 km (124 miles) from the provincial capital Fayzabad and would take the team 12 hours to reach.

The Afghan provincial police spokesperson said in a statement the crash had taken place overnight in a remote, mountainous region of Badakhshan in Afghanistan’s far north.

Aircraft manufacturer Dassault did not respond immediately to a request for comment outside normal business hours.