TOKYO — A 7-year-old boy was missing in a forest in northern Japan after his parents reportedly made him get out of the car as punishment.

About 150 rescue workers resumed searching Monday in a wooded area on Hokkaido, the northernmost of Japan’s four main islands. He had been missing since late Saturday afternoon.

Hokkaido police said the parents initially told authorities that their son had disappeared while they were picking wild vegetables, but an hour later admitted they had made him get out of the car “as discipline.” Police said the father returned to the site a few minutes later but the boy was gone.

The parents told police that it was a punishment for him for throwing rocks while playing at a river earlier in the day, according to Japanese media.