A Boeing 747 cargo plane, belonging to the Kingdom of Saudi Arabia, made a successful emergency landing at Sofia Airport on Tuesday after a false fire warning.

According to the Bulgarian Ministry of Transport, Information Technology and Communications, the cargo jumbo plane carrying volatile substances from Brussels to Riyadh, reported of a fire alarm in the cargo bay while flying over Bulgaria.

Sofia Airport immediately activated its emergency landing procedures, and the plane landed normally, the ministry said.

The airport authorities and the crew then have checked the plane and have found no data on fire.

Investigation of the aircraft's system was still underway, the ministry said.