Refugees are on their way to Vienna in Budaors, about 10 km west from Budapest, Hungary on Sept. 5, 2015. (Xinhua/Csaba Domotor)

BUDAPEST, May 4 (Xinhua) -- Eleven human smugglers were indicted in Hungary for homicide and human smuggling in the tragic case of 71 migrants who suffocated in a closed truck on the motorway linking Budapest and Vienna in 2015, Hungarian News Agency MTI reported Thursday.

The Prosecutor's Office of Bacs-Kiskun county has indicted 11 people, including Afghans, Bulgarians and Lebanese citizens, who left a cooling lorry filled with 71 people on the side of the motorway in Parndorf, Austria in August 2015, chief prosecutor Laszlo Nanasi told reporters on Thursday in Kecskemet, a city in the central part of Hungary.

Then the migrants had already died in Hungary when the vehicle was abandoned on the side of the motorway, according to Nanasi.

The prosecutor said that the criminals had organized the illegal crossing of 1,200 people in 31 occasions through Western Europe, between February and August 2015. They used closed trucks which were unsuitable for human transport.

A 30-year-old Afghan leader of the criminals earned some 300,000 euros (328,000 U.S. dollars) from the illegal transports.