The Indonesian military plane that crashed in a residential part of Medan likely suffered an engine failure, a top military official has told the BBC.

More than 140 people died on Tuesday when the Hercules C-130 exploded in a fireball shortly after take-off.

Air Force chief Agus Supriatna said that one of the engine's propellers was found in a position which indicated it was not working.

Rescue workers have now ended the search for victims of the crash.

The pilot had requested permission to return to base but the plane crashed two minutes after leaving from a nearby airport.

Air Marshal Supriatna said the investigation team had recovered all of the plane's four engines and the abnormal propeller.

He said even though the other three engines were still functional it would have been impossible to control the plane as the problem occurred right after take off.

He told reporters the fact that the plane turned rightward and was flying at a lower-than-normal speed also pointed towards engine failure.

Witnesses on the ground said the plane was tilting and emitting black smoke right before it crashed into two buildings and exploded in a fireball.

'Paying passengers'

The aircraft was carrying more passengers than the military first reported. Authorities had initially only said that 12 crew members were on board the 51-year-old plane and did not mention passengers.

The number was then repeatedly raised, showing confusion about how many people had boarded and alighted during the plane's various stops at different cities.

Family members of those who died told the BBC's Alice Budisatrijo that their relatives had paid to be transported to their destination on the military aircraft, in what would be a violation of military rules.

Various military and government officials have denied this allegation.

This is latest in a series of accident in recent years involving military aircraft. President Joko Widodo has ordered a review of the aging air force fleet and other hardware.