Arab hijackers of a Kuwait Airways jet killed a passenger hostage Monday, then said they will shoot all the passengers, including three members of Kuwait's royal family, if the plane is not refueled.

The gunmen said the dead man, who was tossed out of the plane onto the tarmac, was a "Kuwaiti officer." He was the second man killed by the hijackers, who hold nearly 50 people aboard the plane.Doctors said the side of the man's face was badly injured, possibly because of a beating. He had been shot at least once in the head.

The hijackers warned they would take "more

dangerous steps" if their demand for fuel was not met by Cypriot officials. They said they wanted to fly to a "neutral country."

More than three hours after the man's body was thrown out of the plane at Larnaca airport, the hijackers put one of the passengers, identified as Fadl Marzouk el-Oteibi, on the radio.

Speaking in Arabic, he told the control tower: "The hijackers say that if you don't give us fuel they will kill all the passengers.

"Please listen to this and greetings to my family."

The man's body was thrown out of the jet at 3:07 p.m. (6:07 a.m. MDT), after Cypriot authorities did not comply with several demands that the aircraft be refueled.

Half an hour later an ambulance headed toward the plane, picked up the body and took it to the Larnaca morgue, where AP photo stringer Takis Ioannides said the man was dead on arrival.

"We have executed a Kuwaiti officer," a hijacker told the control tower. "We also reconfirm that the craft must be refueled immediately, immediately, before we take more dangerous steps."

Kuwaiti officials had said three people with "military status" were on the plane.

One of them, a 24-year-old Kuwaiti border guard, was killed Saturday in the first death in the weeklong ordeal.

The hijackers had set two deadlines Monday for fuel. A 1 p.m. (4 a.m. MST) deadline passed without incident after Malaz Abdo, deputy head of the Palestine Liberation Organization office here, and Michael Herodotou, head of Cyprus' Civil Aviation Department, conducted brief negotiations with the hijackers.

The hijackers then set a 2:30 p.m. (5:30 a.m. MST) deadline and told the control tower refueling must start or "you will receive the corpse."

Fourty-seven minutes later, the man, identified by the hijackers as a Kuwaiti officer, was thrown out of the jet.

In announcing the first deadline Monday, one of the gunmen told the control tower by radio: "We hereby appeal to the Cyprus government that we are intending to take off to a neutral country, therefore you are kindly requested within one hour to start refueling the craft. Otherwise, we kill a personality related to the unjust Kuwaiti regime."

The hijackers have been demanding the release of 17 terrorists held in Kuwait for bombing the U.S. and French embassies there in 1983. But sources close to the negotiations said the hijackers Monday demanded freedom for the three men among the 17 terrorists who are sentenced to death.

Kuwait apparently rejected the modified demand.

On Sunday, a pro-Iranian group in Lebanon threatened to kill American and French hostages if any attempt was made to storm the plane. A statement from the Islamic Jihad terrorist group was delivered to a news agency in west Beirut, along with photographs of journalists Terry A. Anderson, an American, and Jean-Paul Kauffmann, of France.

Three members of Kuwait's large Al-Sabah royal family are among the 52 people believed to be aboard the Boeing 747, including at least half a dozen hooded hijackers armed with grenades and guns.

The plane was hijacked Tuesday on a flight from Bangkok to Kuwait carrying 112 people and forced down in northeastern Iran, where 57 people were freed. After the plane left Iran on Friday, Beirut and Damascus refused to let it land.

Another captive, an ailing 32-year-old Kuwaiti, was freed in Larnaca, apparently after PLO intervention.

One member of the royal family, Fadel Khaled Al-Sabah, told the tower by radio Sunday evening in a faint voice: "We depend on God for our fate." The other two royal family members are his sisters, Ebtesam and Anware.

Today marked the first time the hijackers had referred over the radio to any plan to fly to a "neutral country." They did not name the country or say which of the royal family they planned to kill.

However, the Kuwaiti newspaper Al-Qabas reported that Algerian officials have become involved in the negotiations.

At one point, the gunmen had threatened to take off and force the pilot to crash the jumbo jet into the emir's palace in Kuwait City.

On Sunday, the hijackers threatened to start a "slow and quiet massacre" of the 47 or so remaining hostages unless Kuwait released the pro-Iranian prisoners in Kuwait.

The PLO is believed to be a key factor in the negotiations. On Sunday, PLO chief Yasser Arafat joined other Moslem leaders meeting on other issues in Kuwait in supporting Kuwait's refusal to give in to the hijackers' demands.

In Kuwait, pro-government newspapers reported today that additional gunmen boarded the hijacked jetliner at Iran's Mashhad airport and arms and ammunition also were supplied.

Government statements have blamed Iran for the fate of the hostages because Iran allowed the plane to leave Mashhad.

Iran has denied involvement in the hijacking.