A Russian Il-76 firefighting aircraft crossed Bulgarian airspace on Wednesday evening before landing in Serbia, where it has joined efforts to contain large-scale wildfires. Serbian authorities thanked Moscow for the assistance, while the flight also prompted questions in Bulgaria over the circumstances and possible purpose of the Russian aircraft.

The aircraft landed at Nis airport

Aircraft Commander Andrey Vilkov says the city of Nis "is welcoming us with open arms and wonderful people"