The Arab hijackers of a Kuwaiti jumbo jet began beating hostages Saturday after Cypriot authorities failed to meet their deadline to refuel the airliner, the pilot told Larnaca tower.

Airport officials said the pilot radioed at 7:15 a.m. (12:15 a.m. EDT), one minute after the deadline, and said: "The warning has expired, and they've started beating the passengers."Asked if he could see the beatings, he replied "affirmative" and repeated the demand for fuel.

The hijackers issued the ultimatum an hour earlier and said six of the passengers held aboard the Kuwait Airways Boeing 747 were "sick" and the refusal to refuel the jetliner "is causing the sickness," said the officials, who spoke on condition of anonymity.

The jet landed in Cyprus Friday night after being turned away by the Beirut and Damascus airports despite the frantic pilot's cries he had a gun at his head.

The five-day ordeal for the more than 50 people still aboard the jet became more tense when the hooded hijackers issued their ultimatum Saturday, saying also that they would blow up the plane if security men tried to approach it.

Earlier, when the plane was cleared to land, its captain told an air traffic controller: "I'll never forget this thank you."

The blue-and-white jumbo jet touched down at 9:10 p.m. (2:10 p.m. EDT) after circling for 31/2 hours over the Mediterranean following a takeoff from Mashad in northeastern Iran.

Before landing at Larnaca, one of the hijackers ra-dioed the Beirut control tower that panic had broken out aboard the aircraft as it ran low on fuel, with many of the passengers becoming ill.

A woman identified as Anware Khaled Al-Sabah, one of three members of Kuwait's ruling Al-Sabah family on board, got on the radio and told the Beirut control tower in a choking voice: "I beg you. Allow us to land. We have no fuel left."

The tower sternly refused, with the controller telling the desperate pilot at one point: "Do whatever you want. Crash on the tarmac or in the sea . . . We shall not let you land here."

After the jet touched down at Larnaca, a state of emergency was declared at the airport.

Foreign Minister George Iacovou went there to try to establish contact with the hijackers, who are demanding the release of 17 terrorists jailed in Kuwait for bombing the U.S. and French embassies there in 1983. The demand echoed that of pro-Iranian extremists holding U.S. hostages in Lebanon.

The captain, in a calm voice, called the Larnaca Airport's tower and requested fuel but did not say if the hijackers wanted to take off again.

The tower said that since it was a holiday in Cyprus, the airport could only provide him with about 8,000 gallons, less than a quarter of what a jumbo jet can hold.

"Please give us all you can," the pilot responded.

A hijacker then told the tower that if the 17 prisoners in Kuwait were not freed, "the passengers and the plane are in extreme danger."

He said his group's "struggle is against imperialism and Zionism and continuing until martyrdom or victory."

An official Kuwaiti delegation landed at Larnaca on Saturday afternoon and met with Iacovou and Cyprus' interior minister, Christodolos Veniamin, airport officials said.

Cyprus initially closed airports in Larnaca and Paphos, on the island's west coast, to the aircraft. But after Lebanon and Syria also refused to allow the jet to touch down, the captain pleaded for landing permission, saying he was out of fuel. "This is a real emergency," he kept repeating.

The plane had 112 people on board when it was hijacked Tuesday on a Bangkok-Kuwait flight nd diverted to Mashad Airport. The hijackers freed 57 people there on Tuesday and Wednesday.

Those released initially put the number of hijackers at five or six, but diplomats who debriefed the freed passengers in Kuwait said some mentioned as many as 10 hijackers.

Iran originally refused to allow the plane to take off, blocking runways at Mashad, but the hijackers brought a man to the top of the stairway and fired three warning shots, then tossed a grenade out the door, the Islamic Republic News Agency reported. It did not say if it exploded.

A passenger was forced into the cockpit and beaten, said the news agency, monitored in Nicosia. The hijackers first threatened to kill a passenger, then said they would blow the plane up if they weren't allowed to take off.

As the plane left Mashad, the hijackers radioed a message to the emir of Kuwait saying he must comply with their demands or they will blow up the plane, IRNA said.