At least 20 corpses found in truck on Austrian border
The number of dead could be as high as 50, police say.
At least 20 people have been found dead in a lorry abandoned in a motorway lay-by near the eastern border with Hungary, the Austrian authorities say.
The number of dead could be as high as 50, police say.
The grim find comes as a summit focusing on migration takes place in the Austrian capital, Vienna.
Tens of thousands of refugees from conflict-hit states in the Middle East and Africa have been trying to make their way to Europe.
Austria's Chancellor Walter Faymann said the tragedy showed once again "how necessary it is to save lives by combating criminals and people traffickers".
Burgenland police chief Hans Peter Doskozil said motorway police had been alerted to the vehicle - a refrigerated lorry with Hungarian licence plates - which was parked off the A4 motorway between Parndorf and Neusiedl am See.
He told Austrian TV that officers had found at least 20 bodies inside the lorry, but there could be 30, 40 or even 50 inside.
The vehicle was found on Thursday morning but had been there since at least Wednesday, Doskozil said.
The victims had been dead for some time and the bodies had begun to decompose, he added.
The truck bears the logo of a Slovakian poultry company, Hyza, which said in a statement that the vehicle no longer belonged to the firm - but the new owners had not removed the branding.
Hungarian police are working with Austrian police on the investigation, a spokesman for the Hungarian prime minister said.