An Indonesian commercial flight with an estimated 62 people on board has gone missing shortly after take-off from capital Jakarta.
The Sriwijaya Air Boeing 737-500 lost contact en route to Pontianak in West Kalimantan province after taking off just after 2.30pm, officials said.
Flight tracking website Flightradar24.com said the aircraft had lost more than 3,000m (10,000ft) in altitude in less than a minute.
The transport ministry said search and rescue efforts were under way.
It said last contact with the plane, with the call sign SJY182, was made at 14:40 local time.
There were thought to be 56 passengers and six crew on board, though the plane has a capacity of 130.
The usual flight time to Pontianak, in the west of the island of Borneo, is an hour-and-a-half.
Witnesses said they had seen and heard at least one explosion.
Fisherman Solihin said: “The plane fell like lightning into the sea and exploded in the water.”
“It was pretty close to us, the shards of a kind of plywood almost hit my ship.”
It was raining at Soekarno-Hatta International Airport when the plane took off for Pontianak, around 740 km away.
Indonesian Navy has directed all ships in the area to the coordinates where the plane went missing. Rescuers said suspected debris had been found in the sea off the city.
Indonesian television channels showed pictures of the suspected wreckage.
“We found some cables, a piece of jeans, and pieces of metal on the water,” Zulkifli, a security official told local media.
The nearly 27-year-old Boeing 737-500 was much older than Boeing’s problem-plagued 737 MAX model, one of which crashed off Jakarta in late 2018, killing all 189 people aboard the Lion Air flight. Older 737 models are widely flown and do not have the system implicated in the MAX safety crisis.
The Boeing 737 is the world’s most-sold family of aircraft and has undergone several makeovers since it entered service in 1968.