"It is thought to have been caused by a crack in the Nakagawa River Basin sewer pipe. As a result of this collapse, a passing truck fell in," said Saitama's governor Motohiro Ono at a press briefing on Tuesday, adding that rescuing the driver was the primary initiative.

The driver of the truck could communicate with rescue teams when his truck was first swallowed, but there are fears for his safety as sediment fills the hole.

A massive sinkhole opened on a road in Japan's Saitama Prefecture. Rescue efforts are underway a truck that fell into the sinkhole.