LARNACA, Cyprus--A hijacked Kuwaiti jumbo jet took off for Algeria early yesterday after gunmen freed 12 more passengers in what they called a gesture of goodwill.

The blue-and-white Boeing 747 left Larnaca at 1:17 a.m. Wednesday (6:17 p.m. EDT Tuesday) with three members of Kuwait's royal family still among the hostages.

The Shiite Moslem hijackers, who have killed two passengers, had requested charts from the control tower at Larnaca Airport for the three-hour flight to the Algerian capital.

When asked whether the aircraft would be accepted in Algiers, a tower official said a telex from Algerian authorities was "very definite. Yes we will confirm that for you."

About 40 people, including the six to eight hijackers, remained aboard the Kuwait Airways jet. It was commandeered eight days ago on a flight from Bangkok to Kuwait and spent three days at Mashhad, Iran. It was subsequently allowed to land at Larnaca because it was running out of fuel.

Three members of Kuwait's ruling family, Fadel Khaled al-Sabah and his sisters Anware and Ebtesam, still were on the plane, said freed hostage, Dr. George Olympios at Larnaca General Hospital.

A nurse at the hospital said the freed hostages "seem to be OK. There weren't any visible injuries." She added that they were very tired.

Earlier in the day, the gunmen said they had donned "death shrouds" and had dubbed the jetliner "the plane of martyrdom."

The 12 passengers walked off the aircraft at 10:25 p.m. (3:25 p.m. EDT) and got into three ambulances as the flashing lights from the plane and the emergency vehicles illuminated the runway.

After the released passengers left the plane, a hijacker told the tower they were two Palestinians with Jordanian passports and 10 others of unannounced nationality who were sick, poor or whose families had numerous children.

Calling the release a "goodwill" gesture, the hijackers said the Jordanian nationals were freed as a "present to the uprising in Palestine," the 4-months-old Arab rebellion in Israeli-occupied territories.

The hijackers have demanded that Kuwait free 17 pro-Iranian terrorists, all but one of them Shiites, convicted for a chain of bombings there in December 1983. Kuwait refuses to comply.

Negotiators from the Palestine Liberation Organization and the Cyprus government had gone to the airliner earlier in the day. A fuel truck flanked by ambulances drove to the jet.