Police in Bulgaria on February 17 discovered an abandoned truck containing the bodies of 18 migrants who appeared to have suffocated to death.
The Interior Ministry said that according to initial information, the truck was carrying about 40 migrants and the survivors were taken to three hospitals in Sofia for emergency treatment.
Health Minister Assen Medzhidiev said some of the survivors were in very bad condition.
"They have suffered from lack of oxygen, their clothes are wet, they are freezing, and obviously haven't eaten for days," Medzhidiev said.
The truck was abandoned along a highway near Sofia, and the driver fled, according to the Interior Ministry. The people may have been hidden in a shelter built under a load of timber, state news agency BTA reported.
Police received the first report about the truck around 2:15 p.m.
Authorities are working to determine the exact cause of death for the 18 people and the route the truck took. They estimated that the truck had been abandoned for 24 hours.
The Prosecutor-General's Office announced that a nationwide investigation had been launched, and deputy chief prosecutor Borislav Sarafov has arrived on the scene along with Sofia prosecutor Iliana Kirilova.
Safarov announced that three people had been detained but not yet charged.
Authorities did not immediately give the nationalities of the migrants. Bulgarian media reported they all were from Afghanistan.