Investigators are considering several possibilities as to what happened to an Air France jet that disappeared Monday somewhere over the Atlantic Ocean. 228 people were on board.

But while the plane's whereabouts remains a mystery officials say there's no indication of terrorism or foul play.

A massive search began on Monday, although all aboard are feared dead.

Officials say the plane ran into a tower of thunderstorms and heavy turbulence over the Atlantic Ocean.

Hugues Goisbault, French Consul General In Rio, said, "There was very strong tropical turbulence west of the Fernando Noronha Islands. This is all we know about the technical aspect of the accident."

The 4-year-old Airbus A-330, the flight 447 departed from Rio de Janeiro on Sunday around 7pm local time, with 216 passengers and 12 crew members on board.

The plane left Brazilian radar contact, past the Fernando de Noronha archipelago, about three hours later.

Late on Monday the Brazilian Air Force said a commercial pilot saw what appeared to be fire on the ocean near where the plane was believed to have gone missing.

Lieutenant Colonel Jorge Amaral, Brazilian Air Force Spokesperson, said, "A TAM flight saw many orange points in the ocean.It is possible that these were a series of small fires."

On Tuesday, an Air France flight from Rio de Janeiro landed in Paris, a day after the flight 447 on the same route vanished over the Atlantic Ocean.

Meanwhile, relatives of some of the missing passengers have begun to arrive at Rio de Janeiro airport, desperately searching for any information on their loved ones.

If there are no survivors, as feared, it would be the world's worst aviation disaster since 2001.

On board the flight were 61 French citizens, 58 Brazilians, 26 Germans, nine Chinese and nine Italians. A lesser number of citizens from 27 other countries also were on the passenger list.

(CCTV June 3, 2009)