The hijackers of a Kuwait Airways jumbo jet holding about 50 hostages in Mashad, Iran, fired five warning shots at security forces Thursday, and "the situation is presently out of control," the official Iranian news agency reported.

It was not immediately known if anyone was hurt in the shootings.Iran's Islamic Republic News Agency said the hijackers "fired three warning shots at security forces encircling the plane" at 7:25 a.m. EDT and "fired two more shots at the security forces" five minutes later.

"Disciplinary and relief forces are on full alert while the situation is presently out of control, and anything may happen at any moment," IRNA said.

The agency said Iran, which previously rejected two demands from the hijackers to refuel the plane and let it fly elsewhere, agreed to the demand after the shootings.

"Iranian officials stationed at the airport here have finally agreed to refuel the hijacked Kuwaiti airliner after the hijackers' insistence and following their shootings at the security guards," IRNA said.

The agency said the hijackers were "adding to their threats," but it did not elaborate.

It said the taxiway had been closed after the shootings.

The agency later said the refueling was under way. It said the hijackers were insisting the plane take off as soon as possible, but the jet remained on the ground at noon EDT.

The Arabic-speaking hijackers freed another 32 hostages early Thursday, bringing to 57 the number of people set free since the jumbo jet with 112 people aboard was forced to land Tuesday at the Mashad airport, 500 miles east of Tehran near the Afghan and Soviet borders.

IRNA said the 57 people "will be sent to Kuwait by a private plane this evening."

The concierge at the Omar Khayyam Hyatt Hotel in Mashad, contacted by United Press International, said the 57 released hostages "have just left the hotel for the airport and are to be flown home."

In Kuwait, Al-Anba newspaper said six people boarded the plane in Bangkok with false Bahraini and Kuwaiti passports.

It said the the names on the false Bahraini passports were Hamad Al-Julan, Jumaa Zaid Al-Nakhla, Hamdan Rashid Al-Fawar and Ahmad Jaber Al-Mansour, while the Kuwaiti passports were in the names of Saleh Malik and Habib Malik.

Another Arabic-language Kuwaiti newspaper, Al-Qabas, reported the hijackers belonged to the pro-Iranian Lebanese group Hezbollah.

Neither report identified the source of the information.

In Geneva, the International Civil Aviation Organization expressed concern over the hijacking.