At least 12 people were killed and 46 others injured in a series of crashes involving 86 vehicles on Bulgaria's Trakia Motorway, with dense fog suspected to have contributed to the accidents, authorities said.

The pileups occurred near the settlement of Zimnitsa in Yambol Province, involving 63 vehicles traveling toward Burgas and another 23 heading in the opposite direction.

According to preliminary information, the first crash involved two cars that collided and caught fire. A truck, a passenger bus and several other vehicles were subsequently caught up in the collision, triggering further crashes in the opposite lane.

Lyubomir Nikolov, acting chief secretary of Bulgaria's Interior Ministry, said visibility initially dropped from 70–80 meters to around 10 meters, significantly increasing the risk of further collisions.

He added that some drivers may have been distracted by the major crash in the opposite carriageway, contributing to the subsequent pileups.

The accidents left 12 people dead and 46 injured, who were taken to hospitals. The highest numbers of casualties were reported in the provinces of Sliven, Yambol and Burgas. No children were among the dead or injured.

Fifteen fire engines, hundreds of police officers, medical teams and military personnel took part in the rescue operation.

Military Spartan transport aircraft were dispatched to Sofia to prepare for the possible evacuation of seriously injured victims, while hospitals in several cities were placed on alert to receive casualties. (ILKHA)