Security Branch officials have asked the Chinese authorities to stop a growing number of incursions by armed mainland forces intercepting international shipping in local waters. A Security Branch spokesman yesterday confirmed that an incursion on Wednesday, in which armed Chinese police boarded a container ship 'well within' Hong Kong waters, had been taken up with Xinhua (the New China News Agency). 'We have also expressed serious concern about the rising trend of incursion incidents in recent months. We have drawn the Chinese attention to the grave concern expressed in Hong Kong about these incidents. 'We have requested specific assurances from the Chinese authorities that more vigorous efforts will be taken to prevent any recurrence of incidents of this kind,' the spokesman said. The latest incursion took place shortly after midnight on Wednesday when a Hong Kong-based container ship, Xiamen Bridge, was intercepted six kilometres southeast of the Ninepin Islands. Three uniformed Public Security Bureau officers with pistols climbed aboard. They left after checking documents and inspecting the 97-metre vessel, carrying electronic equipment from Xiamen to Hong Kong, for seven minutes. The crewmen believed they were being unfairly targeted as the boat had been intercepted by Chinese officials twice last year.