Iran on November 29 forced a jet carrying Bulgarian Prime Minister Boyko Borissov to leave its airspace, prompting protests from Sofia, in an incident Tehran later blamed on a technical glitch.
Bulgarian Foreign Minister Ekaterina Zaharieva told reporters the plane had all necessary permits to fly over Iran en route to Saudi Arabia late on November 28, but once it entered Iranian airspace, it was asked by Iranian authorities to leave.
Zaharieva said the aircraft had to return to Turkey after what she called an "inexplicable last-moment refusal" by Iran. She said the plane had to get permission to fly through Iraqi airspace, to the west of Iran, before it could reach its final destination, Riyadh.
"The government aircraft had secured all the necessary diplomatic permissions to fly over Iranian airspace," Zaharieva said.
Zaharieva was part of a delegation on board the plane that also included former Bulgarian king Simeon Saxe-Coburg and four other cabinet ministers.
She said Tehran told Sofia the air access refusal was due to a slight deviation of the plane from its planned route. But Bulgarian authorities disagreed and summoned the Iranian charge d'affaires in Bulgaria for an explanation.
The Iranian envoy, Hassan Dotagi, said afterwards he deeply regretted the incident and described it as a "technical misconception."
"The Bulgarian embassy provided the coordinates of the flight and we gave authorization, but the coordinates transmitted by the pilot to the control tower did not correspond with those which had been provided, so they refused the overflight," Iranian Foreign Ministry spokesman Bahram Ghasemi told AFP.
"There was no political intention. We have even given permission for the return flight," he said.