TOKYO—Five people were killed and 12 others taken to the hospital after a truck collided with a bus in Hokkaido in northern Japan, according to local media reports.

Police said the truck might have strayed into oncoming traffic, Kyodo news agency reported. The bus was carrying 15 passengers at the time of the accident, which occurred on Sunday.

The drivers of both vehicles died in the crash, Kyodo said.

Video from broadcaster NTV showed the mangled wreckage of the two vehicles stuck on the road in the aftermath of the crash.

The bus was traveling from Sapporo to Hakodate, and the truck was carrying pigs from Hakodate to Yakumo, Kyodo said.