Six people died and around 20 were injured in an accident involving a German bus and two lorries on Sunday night near Vienna, dpa reported.
The police said the accident happened when the bus hit one of the lorries on the A21 motorway.
Officers refused say where the victims were from as the investigation was ongoing.
The accident took place on an icy road at around midnight roughly 1 kilometre from Heiligenkreuz, the regional headquarters of the emergency services said.
Initial reports said the two lorries - one from Romania, the other from Slovakia - were driving behind one another when the bus with 38 people on board crashed into one of them.
Four of the dead were bus passengers, according to unconfirmed reports.
The police told the German Press Agency dpa that one of the dead was a passenger in a car.