4 arrested after 71 refugees suffocate to death in Austrian truck tragedy

Four people have reportedly been arrested in Hungary after the bodies of 71 refugees were found decomposing in the back of an abandoned lorry in eastern Austria.

The lorry's owner is thought to be a Bulgarian citizen of Lebanese origin, Austrian officials told reporters at a press conference on Friday. Two others arrested were also Bulgarian, and another was Afghan, the police said. 

Austrian police have said that the refugees, including at least four children, died from suffocation.

Austrian police spokesman Hans Peter Doskozil said Syrian travel documents were found in the lorry abandoned on a motorway near the Hungarian border, suggesting the group were "likely" Syrians.

"Among these 71 people, there were 59 men, eight women and four children including a young girl one or two years old and three boys aged eight, nine or 10," he told a news conference.

The lorry was found on Thursday morning on a motorway near the borders with Slovakia and Hungary.

The death toll was originally reported on Thursday as low as 20. News of the increased death toll, confirmed by interior ministry spokesman Alexander Marakovits on Friday, comes as at least 100 migrants were feared dead when two boats sank off the coast of Libya on Thursday. 

The refrigerated, 7.5-tonne lorry had Hungarian number plates and the markings of a Slovakian poultry firm. The driver was nowhere to be seen and Austrian and Hungarian police have launched a joint investigation.

German Chancellor Angela Merkel, in Austria for a summit with Balkan leaders on Europe's migrant crisis on Thursday, said she was "shaken" by the "horrible" news.

"This is a warning to us to tackle this migrants issue quickly and in a European spirit, which means in a spirit of solidarity, and to find solutions," Merkel said.