The Boeing 737, owned by the low-cost airline Lion Air, went down after taking off from the capital Jakarta.
Flight JT 610 was headed for the western city of Pangkal Pinang. Rescuers have recovered some bodies and personal items, including baby shoes.
There is no sign of survivors. The cause of the crash, which involved a plane that had been in operation since August, remains unclear.
The incident is reported to be the first major accident involving a Boeing 737 Max - an updated version of the 737.
"We need to find the main wreckage," said Bambang Suryo, operational director of the search and rescue agency. "I predict there are no survivors, based on body parts found so far."