A drone carrying an explosive device was discovered on Bulgarian territory over the weekend.
The Bulgarian defense ministry said Monday that it sent a special unit to destroy the drone, which was found overnight in the northern city of Tyulenovo on the Black Sea coast of the NATO country.
Tyulenovo is about 30 kilometers from Romania’s southern border and hundreds of kilometers from Ukraine’s Danube River ports which Russia has bombarded with missiles and drones over the summer.
The Bulgarian defense ministry said a five-member team from the Varna Naval Base was sent after a request from the regional governor and the defense chief.
According to Bulgarian media, citizens found the drone on Sunday evening. The investigators discovered that 82 millimeter high-explosive ammunition was attached to the remains of the drone.
Bulgarian Deputy Minister of Defense Yordan Bozhilov reportedly said it is difficult to determine the drone’s origin, and whether it belongs to Russia or Ukraine.
Earlier this month, Romania reported finding debris from a Russian drone on its territory, near the Ukrainian border. Romanian President Klaus Iohannis said Russian drone wreckage landing in Romania would be “a serious violation of the sovereignty and territorial integrity of Romania,” and the country opened an investigation into the remains’ origin.
As NATO members, Bulgaria and Romania are protected under Article 5 of the military alliance’s treaties, which says that an attack on one member will be considered an attack on all members.