HONGKONG officials, increasingly concerned by mainland-sanctioned armed raids on merchant ships leaving the territory, will cite fears for maritime safety in an effort to pressure China to stop the practice. On the same day as another three vessels were chased, and possibly detained, by Chinese border patrol boats, Hongkong officials admit their hand is being forced by growing local and international concern that the new wave of piracy and interceptions will damage the territory's reputation as a safe port. British, United States and Liberian ships have been warned about pirates and armed Chinese patrols in the South China Sea, while the Hongkong Shipowners' Association, whose members include major international firms, is taking a greater interest in threats to local shipping. In an apparent turnaround, senior Marine Department officials are lobbying the Security Branch to persuade China to stop chasing ships on major shipping lanes near the territory. Sources said safety was being touted as a ''diplomatically sensitive'' way of getting China to talk about actions in its own backyard. Previously, both the Marine Department and Security Branch have played down the issue, maintaining that Shenzhen Public Security Bureau and customs officials had the right to intercept ships passing through Chinese waters surrounding Hongkong. Latest figures show that 18 ships heading from Hongkong to Vietnam and Taiwan have been detained so far this year, excluding last night's incident off Po Toi island. Marine Department and shipping industry officials now fear other aborted official raids could be reported as piracy. ''Things are suddenly getting very murky; we could be looking at Chinese officials making pirate raids, or pirates posing as Chinese officials,'' one Marine Department source said. ''One thing is certain, it's Hongkong's reputation that is suffering. It is little comfort that the Royal Navy is looking at what it can do in international waters, because clearly it's going to be powerless to take any sort of action against Chinese patrol boats in Chinese waters.'' Papers are now being prepared for the Secretary of Security, saying constant patrols of small Chinese gunboats in the shipping lanes create confusion, fear and a grave navigational hazard. The hit-and-run collision between an unknown cargo ship and a Chinese border patrol boat in November last year just outside Hongkong waters near Waglan Island will be used as an example. Six people on board the boat died when it sunk as the cargo ship continued uninterrupted on its dawn run to Taiwan. Marine Department officials later handed to Chinese counterparts the name of a ship in the area at the time. They now believe the boat may have been trying to intercept the ship at the time of the collision. The ship is now moored in Hongkong. Marine Department principal surveyor Mr Duncan Drummond said for small boats to chase ships across major shipping lanes was an unreasonable risk. ''It also goes against the training of a master to allow his ship to get close to small boats,'' he said. The director of the Hongkong Shipowners' Association, Mr Michael Farlie, said his organisation was now looking closely at the ''wider issues surrounding interference to merchant shipping around Hongkong'', following an executive committee meeting last week. The association had previously distanced itself from the first wave of Vietnamese ship interceptions last year. ''Now things are increasingly in our backyard, we are working closely with the Hongkong Government,'' Mr Farlie said.