The search for a boy who disappeared after his parents left him behind in a Japanese forest as punishment pushed into a fifth day on Thursday, but with no clues to his fate.

Yamato Tanooka, 7, has been missing since Saturday after his parents made him get out of their car as punishment for misbehaving, leaving him behind in a wooded area on Hokkaido, Japan's northernmost main island.

Police said Thursday's search by more than 180 rescuers, including defense troops, focused on the area where the boy was believed to have been dropped off, and revisiting and combing through the woods.

The case has captured national attention, with many praying for the boy's safe return, while others bitterly criticizing the parents, triggering a debate over whether their treatment of the boy was discipline or child abuse.

Police said the parents admitted they made the boy get out of the car as "discipline," after changing their earlier story that he disappeared while picking wild vegetables.

The parents told police that they were punishing the boy, reportedly for throwing rocks at people and cars while playing at a river earlier in the day.

The father said the boy was gone when he returned to the site several minutes later, police said.

Police said they are considering whether the parents should be charged with child abandonment.