The Lion Air flight JT 610 had been carrying 189 people, including one child and two infants, when it disappeared from radar during a short flight from Jakarta to Pangkal Pinang on the Indonesian island of Bangka, according to Basarnas, Indonesia's national search and rescue agency.
The plane, a new Boeing 737 MAX 8, was carrying 181 passengers, as well as six cabin crew members and two pilots.
Search and rescue teams were working against high waves and strong currents, in an area spanning 150 nautical miles. Underwater robots were being used in the search effort.
Lion Air's plane crashed in Karawang Bay, northeast of Jakarta. The plane crashed about 30 to 40 meters into the deep sea area.