The police in Bulgaria found the bodies of 18 migrants in an abandoned truck near the capital Sofia on Friday.

The Bulgarian Interior Ministry said that according to initial information, the truck was carrying about 40 migrants and the survivors were taken to nearby hospitals.

The country's Health Minister Assen Medzhidiev said most 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.

Officials said that based on initial information, the migrants originated from Afghanistan.

Four Bulgarians have been detained as suspects in the case.

Migrants trafficked to Bulgaria

The truck, which was transporting timber, had hidden the migrants "under some wood" said officials.

The head of the National Investigative Service, Borislav Sarafov, explained that the migrants had illegally crossed the border via Turkey.

They had hid in the woods for two days before being loaded onto the truck in southeastern Bulgaria.

He confirmed that the migrants died from asphyxia and added that given the number of victims, "this is the deadliest incident with migrants in Bulgaria."

Bulgaria: A gateway to Europe

The Balkan country of Bulgaria is located on a major route for migrants from the Middle East and Afghanistan who are seeking to enter Europe through Turkey.

The country of 7 million is the poorest member of the EU.

Bulgaria has erected a 259-kilometer (161-mile) barbed wire fence along its border with Turkey. However, with the help of local human traffickers, migrants continue to enter.

Data from the Interior Ministry reflects that in 2022, the border police thwarted 164,000 "irregular crossing" attempts, compared to 55,000 in 2021.

Mounting criticism against Bulgaria

Sofia has faced mounting accusations of human rights abuses as asylum seekers reported that they have been pushed back, locked up, stripped and beaten.

Bulgarian authorities have denied the accusations.

In December, Austria and the Netherlands blocked the country's bid to join the Schengen border-free zone, over security and rule-of-law concerns.

Bulgaria asked the EU for €2 billion ($2.1 billion) to strengthen the border fence and improve surveillance. Brussels has refused the request.

Previous such incidents 

The gruesome discovery of the recent bodies drew comparisons to previous cases.

In 2015, at the peak of Europe's migration crisis, the bodies of 71 migrants were found piled up in the back of a poultry refrigerator truck in Austria.

A Hungarian court handed three Bulgarians and an Afghan national life prison sentences over the case. 

In 2019,  39 Vietnamese migrants were found dead in a refrigerated truck in Britain shortly after it had crossed over from mainland Europe.

In recent years, several such cases have been reported in Croatia, Ireland, Italy and the Netherlands.

ns/wd (AFP, AP, Reuters)