A drone that entered Bulgarian airspace and exploded near the Trans-Balkan natural gas pipeline close to the border with Romania was not believed to have been part of a deliberate action against Bulgaria, an official said Sunday.
Bulgarian Chief of Defense Emil Eftimov told reporters that the drone may have been diverted by electronic warfare systems before leaving the coverage area of radar systems.
Eftimov said drones of this type can carry up to 5 kilograms (11 pounds) of explosives. Samples have been collected from the wreckage, and authorities are continuing efforts to determine the type of drone involved.
"There was no deliberate action against Bulgaria," he said.
Meanwhile, Bulgarian Foreign Minister Velislava Petrova summoned Ukrainian Ambassador to Sofia Olesya Ilashchuk to the Foreign Ministry over the drone's entry into Bulgarian airspace.
The drone was believed to belong to the Ukrainian military, according to Bulgarian authorities.
The Bulgarian Foreign Ministry said the meeting would take place Monday because Ilashchuk was outside the country.
