'Chechen' hijackers free women and children

No women or children are thought to be left on board

The hijackers of a Russian plane forced to land in the holy Muslim city of Medina have freed at least 20 women, children and the elderly while their negotiations with Saudi officials continue.

Another group of about 15 hostages was reported to have escaped the aircraft from a rear exit.

A Kremlin spokesman said the pilots have barricaded themselves in the cockpit, and the hijackers had no access to them.

The hijackers, claiming to be Chechens and armed with bombs, seized control of the Vnukovo Airlines jet carrying more than 160 people after a struggle about half an hour into the 1130GMT flight from Istanbul to Moscow.

There are conflicting reports over the number of hijackers involved, with Saudi media suggesting there are four and not two as initially believed.

The aircraft has been surrounded by the security forces and a Saudi team is negotiating with the suspected Chechens.

The plane, a Tupolev 154, plunged 400m as a fight broke out at the door of the cockpit involving the hijackers.

The aircraft was eventually stabilised, but one man was injured in the struggle. His condition was reported to be critical, and he is now believed to among those released.

Hijackers' demands

Russian President Vladimir Putin has set up a special crisis team headed by the deputy director of the security services to monitor developments.

People look for their relatives on the plane's passenger lists

Most of the passengers were reported to be Russians, along with between 55 and 60 Turkish nationals.

The hijackers have issued a list of demands which, according to the head of Vnukovo Airlines, Alexander Klimov, include an end to Russia's military campaign in Chechnya.

Some reports suggest the men want permission to fly on to Afghanistan.

A Russian foreign ministry spokesman said Moscow was calling on the Saudi Government to ensure the safety of the hijacked aircraft and for the hijackers to be handed over.

The holy city of Medina

Second holiest place in the Muslim world after Mecca

Closed to all non-Muslims

Site of the Prophet Mohammed's Mosque which contains his tomb

Moscow has often accused Turkey of supporting the rebels in the breakaway republic of Chechnya, saying it provides financial and material aid.

The overwhelming majority of Turks and Chechens are Muslims and more than 20,000 Chechens live in Turkey.

In December 1999, Turkey and Russia signed an agreement to combat terrorism after Turkey reportedly promised to stop all support of the Chechens.

Qatari Al-Jazirah TV says the hijackers might have chosen Medina in the belief that no foreign forces would be able to intervene since, according to Muslim law, the city is closed to all non-Muslims

This is the fifth hijacking from a Turkish airport since 1998.

The last was in 1999, when a man armed with a knife seized control of a Cairo-bound flight shortly after take-off from Istanbul.