The aircraft lost contact with air traffic control around 6.30 am (2330 GMT), about 13 minutes after it took off, bound for Pangkal Pinang on the island of Bangka off the coast of Sumatra island.
“It’s true that Lion Air JT 610 has lost contact. We have forwarded the information to search and rescue teams,” AirNav Indonesia spokesman Yohanes Harry Douglas said in a statement.
Slamet Waluyo, police chief from Karawang district in Jakarta’s east — near the closest point to the suspected crash site — said authorities had received reports from several sources that the plane had crashed into the sea.
“At the moment personnel from Karawang water police unit are heading to the coordinates to check whether the information we received was accurate,” Waluyo told broadcaster Kompas TV.
It was not clear how many people were on board the flight, which the Flightradar website said was a Boeing 737.
The website tracked the plane, showing it looping south on take-off and then heading north before the flight path ended abruptly over the Java Sea, not far from the coast.
Indonesia relies heavily on air transport to connect its thousands of islands but has a poor aviation safety record and has suffered several fatal crashes in recent years.
A 12-year-old boy was the sole survivor of a plane crash that killed eight people in mountainous eastern Indonesia in August.
In August 2015, a commercial passenger aircraft operated by Indonesian carrier Trigana crashed in Papua due to bad weather, killing all 54 people on board.
Lion Air, a low-cost airline, has been involved a number of incidents.
Last year one of its Boeing jets collided with a Wings Air plane as it landed at Kualanamu airport on the island of Sumatra, although no one was injured.
In May 2016, two Lion Air planes collided at Jakarta’s Soekarno-Hatta airport, while a month earlier a plane operated by Batik Air — part of the Lion Group — clipped a TransNusa plane.
In 2013 a Lion Air jet with a rookie pilot at the controls undershot the runway and crashed into the sea in Bali, splitting the plane in two. Several people were injured in the crash, although no one was killed.
Indonesia’s air travel industry is booming, with the number of domestic passengers growing significantly over the past decade, but it has acquired a reputation for poor regulation.
Last year the Indonesian air traffic controllers association revealed that the rate of take-off and landings in Jakarta allowed by state-run air navigation company AirNav was more than the airport could handle, increasing the chance of accidents. DM