At least 19 people have been killed and 23 injured after a passenger bus 'flipped over' on a highway in Argentina.

The bus was en route from the Argentine city of Mendoza to Santiago, Chile, and had 42 people on board when it overturned on Route 7 of the Pan-American highway shortly after midnight on Saturday, according to police.

Route 7 is a remote mountain road that winds through the Andes.

The accident happened near the Aconcagua Provincial Park - which includes the highest mountain in the Americas - and resulted in the highway being closed for several hours.