31.   Authorities were investigating whether the explosion that brought down the jetliner was the result of foul play, or of some kind of mechanical trouble.

32.   Forest Service spokesman Warren told AFP that there were unconfirmed reports that the crew reported mechanical troubles shortly before the crash.

33.   The reports said there might have been mechanical trouble with the flight control system.

34.   The newspaper report said analysts had ruled out sabotage or mechanical trouble as the cause of the accident.

35.   The pilot did not make contact with the nearby airport, Santa Elena, to report mechanical trouble, Munoz said.

36.   The pilot of the Air China jet which crashed in South Korea said Tuesday that he had felt no mechanical troubles before the disaster, officials said.

37.   The plane developed mechanical trouble and crashed in the outskirts of the city as the pilot tried to turn back to the airport, police said.

38.   The plane developed mechanical trouble but crashed in the outskirts of the city as the pilot tried to turn back to the airport, police said.

39.   US Forest Service spokesman Larry Warren told AFP that there were unconfirmed reports that the crew reported mechanical troubles shortly before the crash.

40.   Warren said there were unconfirmed reports that the crew reported mechanical troubles shortly before the crash.