Bulgaria’s government says at least 18 people, including a child, have been discovered dead inside an abandoned truck.
About 40 migrants appeared to have been being illegally transported by the vehicle. The survivors were transported to a hospital for medical attention.
According to the health minister, the people in the truck were chilly, damp, and hungry after several days.
It is thought to be the most fatal immigrant-related incident to have occurred in Bulgaria.
Large numbers of people attempting to enter the European Union from Turkey have long caused Bulgaria problems.
The truck, found near the village of Lokorsko, 12 miles (20 km) north-east of Bulgaria’s capital, Sofia, was illegally transporting the migrants hidden under some wood, the interior ministry said.
Health Minister Asen Medzhidiev described the conditions inside the truck: “There has been a lack of oxygen for those who were locked in this truck.””They were freezing and wet, and they hadn’t eaten in days.”
Fourteen people found alive in the truck, including eight in serious condition, were taken to the hospital, he added, while another 10 people were found hiding nearby and would be taken to the hospital for examination.
Police are searching for the human traffickers believed to have driven the truck and fled, officials said.
Bulgaria has faced accusations that it is abusing people attempting to enter from Turkey, with asylum seekers saying they have been blocked, arrested, stripped, and beaten.