JAKARTA:Indonesian ships with rescue divers and equipment to detect signals from a flight recorder resumed the search on Sunday for a Sriwijaya Air jet believed to have crashed into the sea minutes after takeoff from the Indonesian capital Jakarta.

The Boeing 737-500 with 62 people on board was en route to Pontianak in West Kalimantan before it disappeared on Saturday from radar screens four minutes after takeoff.

Search teams and fishermen have retrieved some debris and a section of an emergency chute believed to come from the jet in the seas off Jakarta but have yet to find the fuselage or confirm the fate of the passengers and crew.

"We have prepared all the equipment and are ready at the spot where the debris was found yesterday," Muhammad Yassin, director of marine police (POLAIR) told the TVOne channel from navy vessel KRI Gilimanuk.

POLAIR will focus its search on the outer ring of the Laki and Lancang islands off the Jakarta coast, he said. The sea in this area is about 20 to 23 metres (65-75 feet) deep.

A diver involved in the search and rescue operation interviewed by Kompas TV said his team had an underwater metal detector and a pinger locator to deploy in an effort to pick up signals for the plane's black box.

Helicopters were also on standby at an airport near Jakarta to launch a search from the air.

The Indonesian meteorological agency has warned of a risk of heavy rain and strong winds that could hamper the search and rescue efforts.

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.

"We are in contact with our airline customer and stand ready to support them during this difficult time," Boeing said in a statement. "Our thoughts are with the crew, passengers, and their families."

Distraught relatives waited at Pontianak about 740 km (460 miles) from Jakarta for news of their loved ones. At Jakarta's main airport a crisis centre was set up for relatives.

Founded in 2003, Jakarta-based Sriwijaya Air group flies largely within Indonesia. The budget airline has had a solid safety record, with no onboard casualties in four incidents recorded on the Aviation Safety Network database.

In 2007, the European Union banned all Indonesian airlines following a series of crashes and reports of deteriorating oversight and maintenance since deregulation in the late 1990s. The restrictions were fully lifted in 2018.

Between 2007 and 2016, the U.S. Federal Aviation Administration lowered its Indonesia safety evaluation to Category 2, meaning its regulatory system was inadequate.