VIENNA: Six people were killed and 37 injured Monday after an overnight collision between a tourist bus and two trucks near the Austrian capital of Vienna.

The tour bus had a Munich-registered license plate, and was believed to have been en route from Kosovo. The nationality of the victims remained unclear, but the majority were also thought to be Kosovars, police said.

Some of the passengers were Serbians, hospital staff told the German Press Agency dpa, though it was unclear if they were Serbian citiziens, or ethnic Serbians living in Kosovo.

The two trucks were registered in Romania and Slovakia.

According to the police, the accident happened when the bus, carrying 38 people, and the two trucks collided. The bus driver and five people in the front seats were killed.

The Slovakian truck driver was said to have suffered life- threatening injuries, whilst the Romanian driver had minor injuries.

No exact details about how the accident happened were available.

Reports of icy roads were denied early on Monday. A spokesman for the highways agency said that the roads were dry.

It was also unclear how the three vehicles had collided with each other. The two trucks may have already collided before the bus drove into them, but the bus could also have caused the crash, said Willy Konrath, the head of Lower Austria's transport department.