BELGRADE, Serbia (AP) — Police in Serbia say two multi-vehicle crashes on a key highway during dense morning fog have killed six people and injured at least 27.

The statement says the two crashes early Tuesday involved a number of cars and trucks and probably happened because of the fog.

Serbian state TV reported that some victims were still stuck in their crashed cars and rescuers were pulling them out. The report says the collisions took place on both sides of the main north-south highway in central Serbia. Traffic has been halted in both directions.