Over 70 found dead in lorry in Austria believed to be Syrian

Seventy-one people found dead in the back of a truck left on the side of an Austrian highway are believed to be Syrian asylum seekers and likely suffocated, police said Friday.

Hungarian authorities detained three men in relation to Thursday's gruesome discovery: a Hungarian-Lebanese national who owned the lorry and two other men - one Bulgarian and one Hungarian - who were driving the vehicle.

The three men are thought to form "the two lowest rungs of an organized crime network" and were likely to lead to other perpetrators, said Hans Peter Doskozil, police chief of Burgenland, the state on the Hungarian border where the lorry was found.

Four other people had also been detained but were later released, he said.

Doskozil said one set of Syrian documents was found in the lorry, leading investigators to believe that the 59 men, eight women and four children found dead inside were refugees fleeing via the Balkans from war-torn Syria.

An investigation is under way to definitively determine the cause of death, identify the victims and determine who is responsible for the trafficking network behind the crime.

Employees of the highway operator Asfinag discovered the 7.5-ton lorry abandoned on the shoulder of the highway near Parndorf, about 50 kilometres south-east of Vienna.

The truck was taken to a veterinary institute with refrigeration facilities, and about 20 forensic experts worked through the night to remove and count the bodies.