Drones and sonar technology have been deployed in Indonesia to search for a Lion Air passenger plane which crashed into the sea on Monday.
Flight JT 610 went down after taking off from Jakarta with 189 passengers and crew on board.
There has been no sign of survivors but debris and personal belongings have been collected from the water.
There is no indication yet of what caused the plane to go down 13 minutes after taking off.
Officials say the pilot of the Boeing 737, which was heading for the western city of Pangkal Pinang, had asked to return to Soekarno-Hatta airport shortly before losing contact with air traffic control.
A log obtained by the BBC showed the plane had encountered technical problems while flying from Bali to Jakarta the previous day.
The log showed one instrument was giving "unreliable" airspeed readings and the captain had to hand over to the first officer. Altitude readings also differed on the captain and first officer's instruments.
Lion Air's chief executive Edward Sirait said on Tuesday that the plane had been repaired before taking off again.
The plane plunged in coastal waters that are about 30m (100ft) deep north-east of Jakarta.
Investigators say they are hopeful of finding the main fuselage. Search teams are using an underwater drone, as well as underwater "pinger locators" to try to pick up the sonar signals from the cockpit recorders.
Search teams have been retrieving body parts, aircraft debris and personal items.
Body bags are being taken to Jakarta for identification.
Another search official, Yusuf Latif, earlier said it would be "a miracle" if survivors were found.
Mr Sutopo has also warned against hoaxes that have been spreading on social media, including pictures that users claimed were taken by passengers in their last moments before the plane went down.