A HONGKONG security firm is considering a request from an international aid agency to provide 200 escorts for more than 500 Chinese illegal immigrants during repatriation flights from the Marshall Islands. Diplomatic sources said last night that flights carrying the passengers from the Hongkong-operated freighter East Wood were expected to leave tomorrow, pending assurances given by China to the United States that the immigrants would not be persecuted on their return. In an issue that appears to be growing in sensitivity, talks are under way in Beijing and Washington involving the US, China, the Marshall Islands and the East Wood's flag state, Panama. The US has said it is not responsible for migrants, having only rescued them in the mid-Pacific after bogus hijacking reports. The UN High Commissioner for Refugees opened the way for their repatriation after declaring all the passengers to be economic migrants and not asylum seekers. A team from the International Organisation for Migration (IOM), headed by Hongkong chief of mission Dr Alfred Kottek, is arranging the flights through the Hongkong company Far East Air Charters. IOM assists in repatriations by the United Nations. A Boeing 767 and a Hercules transport plane are understood to be on stand-by. The IOM has approached Jardine-Securicor to provide unarmed escorts, fearing the migrants could turn violent after claims that they will be jailed or fined for their attempts to flee China. Jardine-Securicor's chief executive, Mr Percy Weatherall, confirmed that his company had been approached but said the deal was still being considered. ''Clearly there's a job to be done and we're in the sort of business to do it,'' Mr Weatherall said. ''It's more complicated than most of our business so we've got to give it a great deal of commercial consideration.'' IOM approached the company after the Hongkong Government turned down earlier US requests for assistance. It is understood the repatriation will be run through the US air base in Guam, with a US consulate official from Hongkong already on the island to issue transit visas to speed up the flight to Xiamen, in the Chinese province of Fujian. Most of the migrants are Fujianese. The US Government is bankrolling the repatriation, but is seeking to force Panama - and possibly the Korean-based owners of the East Wood, which is managed in Hongkong - to foot the bill. Diplomats in Hongkong said the repatriation was being seen as a vital test case if an explosion of Chinese migrants cramming themselves aboard freighters was to be avoided. ''Everyone's watching how the Marshall Islands situation develops,'' one diplomat said. ''That's where the precedents will be set that could avoid some sort of new boat-people boom. It's clear no one really wants them.'' Mr Tang Chan-pui, managing director of Konwa Shipping, which used to manage the East Wood, said the Hongkong-based representatives of its Korean owners were now in the Marshall Islands trying to secure the freighter's release. Meanwhile, Hongkong police and officials from the US and Canadian consulates are seeking more information on reports that Chinese border police have arrested more than 200 men and women trying to board a wooden ship in the coastal town of Dianbai in southern Guangdong province.