An Indonesian Sriwijaya Airplane is feared to have crashed into the sea after the Boeing 737 lost contact with air traffic control in the capital Jakarta with flight tracking data showing it plunged into a steep dive just minutes after take-off.

The aircraft was carrying more than 60 people when communications dropped off on Saturday. A statement released by the budget airline said the Boeing 737-500 was on an estimated 90-minute flight from Jakarta to Pontianak, capital of West Kalimantan province on Indonesia’s Borneo island.

It was raining at Soekarno-Hatta International Airport at the time of take-off for Pontianak, around 740km (460 miles) away.

A source at the airport told said that there were 46 adults, seven children, and three infants on board along with six crew members. Boarding was delayed because of heavy rain.

Surachman, a local government official, said that fishermen found what appeared to be the wreckage of an aircraft in waters north of Jakarta. local news channels showed images of suspected wreckage.

“We found some cables, a piece of jeans, and pieces of metal on the water,” Zulkifli, a security official, told a local news channel.

Agus Haryono, an official of the Basarnas search-and-rescue agency, told Reuters news agency it had not been confirmed the debris came from Sriwijaya Air Flight SJ182. Agus said 50 people were taking part in the search and they would keep working into the night.

Reliable tracking service Flightradar24 said on its Twitter feed that Flight SJ182 “lost more than 10,000 feet [3,000 metres] of altitude in less than one minute, about 4 minutes after departure from Jakarta”.

Television footage showed relatives and friends of people aboard the plane weeping, praying, and hugging each other as they waited at Jakarta’s airport and Pontianak’s airport.

Indonesian transportation ministry spokeswoman Adita Irawati said in a statement the missing plane is currently under investigation. “It last made contact at 2:40pm [07:40 GMT],” she said.

The aircraft is a 27-year-old Boeing 737-500, according to registration details included in the tracking data.

“Many airlines in Indonesia have had issues in the past but this is a story that has caught many people off guard as Sriwijaya Air does have some reliable history,” a source said.

A Boeing spokeswoman said: “We are aware of media reports from Jakarta and are closely monitoring the situation. We are working to gather more information.”