(CNN) — Dozens of refugees — most likely fleeing war-ravaged Syria — died of suffocation inside an abandoned truck on an Austrian highway, authorities said Friday.
The 71 victims were 60 men, eight women and three children — ages 2 3, and 8, officials said.
“They probably suffocated inside the truck. We are talking about human trafficking, homicide, even murder,” said Johann Fuchs, state prosecutor of Eisenstadt.
“We are likely looking at a Bulgarian-Hungarian people smuggling ring.”
Officials found a Syrian travel document inside the truck.
“We must assume now that these are refugees,” said Hans Peter Doskozil, police director of Austria’s Burgenland region. “In concrete terms, it is possible this is a Syrian refugee group.”
The truck was found Thursday, abandoned on the side of the A4 highway, which links Budapest in Hungary to the Austrian capital, Vienna. When police opened the back of it, they found the bodies decomposing in the heat.
About 3,000 trucks pass through that area of the highway daily, and checking each one of them is almost impossible, authorities said. Most human smugglers use smaller cars, making the use of trucks unusual.
Hungarian police said Friday they had arrested four people in connection with the truck. The arrests include three Bulgarian citizens and an Afghan citizen, Hungarian police said.
The grim discovery came just a day after the Italian coast guard said 54 people lost their lives trying to cross the Mediterranean. It highlighted once again the scale of the migration crisis gripping Europe.
“This horrible crime shows that we must get even tougher in the battle against people smuggling,” Austrian Interior Minister Johanna Mikl-Leitner said at a news conference.
“People smugglers are criminals and not well-minded helpers. They do not care about the well-being of the refugees, they care about profit.”
In addition to the deaths of refugees trying to cross into Europe by roads, hundreds are making the perilous journey by sea.
The number of deaths of all migrants and refugees attempting to reach Europe by sea in 2015 stood at 2,373 as of this week, the International Organization for Migration said.
The death toll for all of last year was 3,281, and experts fear the numbers could skyrocket if unseaworthy boats carrying migrants continue to make the treacherous journey.