A Lion Air Boeing 737 passenger plane with 189 people on board has crashed into the sea shortly after taking off from the Indonesian capital, Jakarta.
Flight JT 610 was headed for Pangkal Pinang, in the Bangka Belitung Islands, when it lost contact.
Rescuers have recovered some remains and there is no sign of survivors.
The cause of the crash, involving a new plane in operation since August, remains unclear. Lion Air is Indonesia's largest low-cost carrier.
The incident is reported to be the first major accident involving a Boeing 737 Max - an updated version of the 737.
"The plane crashed into water about 30m to 40m deep," Search and Rescue Agency spokesman Yusuf Latif told AFP news agency. "We're still searching for the remains of the plane."
Rescuers have recovered body parts from the sea. Items believed to belong to passengers have also been found in the water, including baby shoes, ID cards and driver's licences.
"We don't know yet whether there are any survivors," the agency's head, Muhmmad Syaugi, told reporters. "We hope, we pray, but we cannot confirm."
At an earlier news conference, officials said the plane had been carrying 178 adults, one infant and two babies, as well as two pilots and five cabin crew. However, Lion Air has since named six cabin crew.
Distraught family members of those on board have been gathering at Jakarta's Halim Perdanakusuma Airport as they wait for news.