Police are searching for the driver of a van in Austria which was found to contain nearly 30 people crammed into a small space, two of whom had died.
The migrants were found dead in the van intercepted at the Hungarian border on Tuesday, police told AFP.
The army checked the vehicle, which they found suspicious, and discovered 26 people alive, and two dead. All the migrants found in the van were men from Syria, according to initial findings.
The driver of the vehicle fled on foot, and is currently being sought.
"This terrible act clearly shows one thing: the death of one or more people is deliberately accepted by the traffickers," said conservative Austrian Interior Minister Karl Nehammer.
Austria, which has seen an influx of migrants at its eastern and southern borders, stepped up controls in July.
Two hundred and fifty smugglers have been arrested since the start of the year, police said.
The east of the country had already been the scene of a similar drama a few years ago.
On 27 August 2015, 71 illegal immigrants from Syria, Iraq and Afghanistan, including three children and a baby, died of suffocation in the airtight compartment of a van, where they had been hidden by the smugglers.
They were discovered in Austria, but died while still on the other side of the border. Almost four years later, the Hungarian courts sentenced their smugglers to life imprisonment.
The emotion generated by the case helped to temporarily open the borders to hundreds of thousands of people seeking to reach Western Europe at the start of the 2015-2016 migration wave.