Bulgaria’s Foreign Ministry allowed a Russian plane allegedly transporting diplomats to use its airspace en route to Syria on Monday, September 7, the ministry’s press service hsa said.

The announcement comes amid a diplomatic row between Sofia and Moscow caused by the former’s decision not to grant on Tuesday passage to a plane which Russia says was carrying humanitarian aid to Syria.

The day before the Foreign Ministry, says, it had no formal right whatsoever to deny overflight. But on September 8, it had received information that the plane would be carrying weapons to Syria, instead of humanitarian aid. The move raised tensions between Russia and Bulgaria, with Moscow demanding an explanation and questioning Bulgaria’s sovereignty.

According to flightradar24, a flight-tracking website, the September 7 plane entered Bulgaria at 14:20 EEST and left after 15:00, crossing into Greek airspace and then flying over the Mediterranean to reach the port of Latakia in Syria.

FlightRadar describes the aircraft as an Ilyushin Il-62M, a passenger jet and not a military plane, despite reports in Bulgarian media outlets suggesting otherwise (the report run by TASS [RU], however, uses a picture of Il-76, a multi-purpose cargo and transport plane which has both civilian and military versions).