VIENNA (AP) — The number of migrants found dead in a truck abandoned on Austria's main highway to Hungary has risen to more than 70, the Interior Ministry said Friday.

The count reported Friday by Interior Ministry official Alexander Marakovits is significantly higher than the estimate of 20 to 50 that authorities gave Thursday after finding the refrigerated truck parked on the safety lane of the main highway connecting Vienna and Budapest, Hungary.

The newest figure comes from a body count late Thursday. The truck was towed then to a refrigerated warehouse near the border with Hungary to allow police and forensic experts to remove the victims, try to identify them and start on autopsies meant to determine how they died.

Police in eastern Burgenland province, where the tragedy occurred, were not releasing details of their investigation ahead of a news conference scheduled for late Friday morning.

But the Kronen Zeitung newspaper reported that three suspects believed to have been involved in smuggling the migrants had been arrested in Hungary.