All 121 people on board a Cypriot airliner are feared dead after crashed into a hill near Athens. A text message sent from the plane said that the pilots were unconscious and passengers were freezing to death.

Greek F-16 fighter jets were scrambled when contact with the Helios Airways plane was lost during the flight between Larnaca in Cyprus and Athens.

Relatives of some of the passengers gathered anxiously at Larnaca airport, and complained they had waited for hours without being told of their loved ones' fates. Information on passenger manifests was was not forthcoming.

Airline officials said the plane was due to fly on to the Czech capital Prague after a stopover in Athens.

Larnaca airport authorities told Cyprus state TV a sudden drop in cabin pressure may have knocked out the pilots.

Greek TV reported that a passenger sent a text message to a cousin telling him that the pilot had turned blue in the face and the plane's temperature had plummeted.

There were initially suspicions the plane might have been hijacked, but these were swiftly ruled out by Greece's foreign ministry.

A Greek government spokesman said the first indication was that the crash was an accident.

Helios Airways was founded in 1999 as Cyprus' first independent airline. It operates a fleet of Boeing 737 jets