CAIRO, Egypt (AP) _ An Egyptian airliner that had been diverted to Alexandria because of sandstorms crashed Tuesday as it was returning to Cairo, and at least 20 people were killed, officials reported.

Officials said there were six survivors but one died later in a hospital.

The government's Middle East News Agency said the twin-engine Fokker-27, operated by Air Sinai, had been cleared to land at the Cairo International Airport when it slammed into the courtyard of a construction company and burst into flames at about 7:30 p.m. (11:30 a.m. EDT).

The plane crashed about a mile from an amusement park jammed with people celebrating the final day of a four-day religious holiday.

Montaza Sadeddin, deputy commander of a local police station, said the plane came down on a highway about 750 yards from a runway at the airport, located in the desert on the Cairo's eastern edge and skidded into the construction company compound.

Officials said they had no information on nationalities of the victims but most were believed to be Egyptians.

''I heard an explosion and found a huge fire in the courtyard,'' said Sayed Nur el-Din Mustafa, an employe of the construction company.

''We started to put it out with fire extinguishers,'' he said. ''We found five people thrown from the wreckage and a sixth person pinned beneath it. We put them in a company ambulance and took them to the hospital straightaway.''

Airport officials said the plane originally was bound for Cairo from the Sinai resort of Sharm el-Sheik when it was diverted to Alexandria because of sandstorms here.

Later, the plane began its return flight to Cairo after weather conditions improved, the officials said.

Airport sources, speaking on condition they not be identified, said pilots of an Iraqi Airways plane and a Lufthansa jetliner radioed the control tower that they saw flames from one of the Air Sinai craft's engines moments before the crash.