JAKARTA, Indonesia (AFP) — An Indonesian budget airline plane with 62 people on board is suspected to have crashed into the sea shortly after the Boeing 737 took off from Jakarta airport on Saturday, authorities said.

Flight tracking data showed the Sriwijaya Air Boeing 737-500 plunged into a steep dive about four minutes after it left Soekarno-Hatta international airport.

Sixty-two passengers and crew were on board, including 10 children, the nation’s transport minister, Budi Karya Sumadi, told reporters.

The suspected crash site is near tourist islands just off the coast of Indonesia’s sprawling capital.

Sriwijaya Air flight SJ182 was bound for Pontianak on Indonesia’s section of Borneo island, about 90 minutes flying time over the Java Sea.

Distraught relatives waited nervously for news at the city’s airport.

“I have four family members on the flight — my wife and my three children,” Yaman Zai said as he sobbed.

“(My wife) sent me a picture of the baby today…How could my heart not be torn into pieces?”

The plane took off on Saturday afternoon and a search and rescue operation began with no official results available on Saturday night.

“We deployed our team, boats and sea riders to the location suspected to be where it went down after losing contact,” Bambang Suryo Aji, a senior official at the search-and-rescue agency, told reporters after nightfall.

– Sudden plunge –

Data from FlightRadar24 said the plane reached an altitude of nearly 11,000 feet (3,350 metres) before dropping suddenly to 250 feet. It then lost contact with air traffic control.

“Sriwijaya Air flight #SJ182 lost more than 10,000 feet of altitude in less than one minute, about 4 minutes after departure from Jakarta,” the tracking agency said on its official Twitter account.

Broadcaster Kompas TV quoted local fishermen as saying they had found debris near islands just off the coast of the capital Jakarta, but it could not be immediately confirmed as having belonged to the missing jet.

Authorities and the airline gave no immediate indication as to why the plane suddenly went down.

The budget airline, which has about 19 Boeing jets that fly to destinations in Indonesia and Southeast Asia, said only that it was investigating the loss of contact.

In October 2018, 189 people were killed when a Lion Air Boeing 737 MAX jet slammed into the Java Sea about 12 minutes after take-off from Jakarta on a routine one-hour flight.

That crash — and a subsequent fatal flight in Ethiopia — saw Boeing hit with US$2.5 billion in fines over claims it defrauded regulators overseeing the 737 MAX model, which was grounded worldwide following the two deadly crashes.

The Boeing jet thought to have crashed Saturday is not a MAX model.

“We are aware of media reports from Jakarta, and are closely monitoring the situation,” the US-based planemaker said in a statement.

“We are working to gather more information.”