Beijing has again denied permission for a US navy maritime surveillance aircraft to land in Hong Kong but allowed two military ships to dock in the harbour. Defence analysts said the continuing refusal to allow the P3 aircraft to enter SAR airspace appeared to indicate the PLA believed it would be used to gather intelligence. Approved were the navy's fast combat support ship Sacramento and the Coast Guard cutter Midgett which are scheduled to arrive on November 25 and stay for four days. Three other requests for the P3 aircraft, used for surveillance and submarine hunting, to land have also been refused since Nato bombed the Chinese Embassy in Belgrade in May. The port visit of a US navy destroyer last week marked the arrival of the first ship with offensive capabilities since Beijing began its ban on US military visits to Hong Kong. A US Consulate spokesman said the aircraft would have been on an exercise to practise 'over-water navigation'. The Chinese military had other suspicions, said analyst Paul Beaver of Jane's defence group. 'It's a maritime aircraft and it's crammed with electronic surveillance equipment,' he said. 'They would be thinking it is trying to gather signals and intelligence as it flies in and out.' The USS Sacramento, with 618 crew, is tasked with replenishing at sea other navy ships with petroleum, munitions, provisions and freight. Since the curtailment of US military visits to Hong Kong began, five ships have been permitted to conduct port visits and 10 refused. Five aircraft were allowed to land and six denied. 'We view such routine stopovers as evidence of Hong Kong's autonomy and hope that access to Hong Kong's facilities will be afforded,' said the consulate spokesman.