Abu Dhabi - Four Americans aboard a turboprop plane were killed when their aircraft crashed shortly after takeoff in the United Arab Emirates, US and Emirati officials said Monday.

Investigators were examining the wreckage to determine a possible cause for the fiery Sunday evening crash. The identities of those killed _ the only people on board _ were not immediately disclosed.

A statement by the US Embassy to local media said the plane was en route to Riyadh, Saudi Arabia, on the first leg of a trip back to the United States.

The twin-engine plane _ apparently a vintage aircraft that had been modified _ went down moments after taking off at Al Ain International Airport about 60 miles (100 kilometers) east of Abu Dhabi. A statement by the UAE's Civil Aviation Authority said it crashed the taxiway before catching fire.

The plane was reported to be a McKinnon Turbo Goose G21G, which is a version of an earlier Grumman G21 aircraft converted from piston engines to turboprops.

The Abu Dhabi-based newspaper The National reported the plane is owned by Triple S Aviation, a Texas-based aircraft service company with a branch office in Dubai. The company's website says it offers business aircraft, helicopters, and special use aircraft to the Middle East and South Asian markets.