Mainland security officers had to trudge a kilometre in wet uniforms yesterday to use a shop's phone to tell their families of their narrow escape. Onlookers said soaking crewmen rescued from a blazing patrol vessel and taken back to their Shenzhen base had made the long-distance calls home - then confessed they were unable to pay because their wallets had been lost at sea. One officer told his family in Hunan: 'I almost lost my life on duty today. 'We were heading for a job but the engine caught fire. We ran on to the deck and jumped into the water. I'm glad I'm still in one piece - the fire was huge,' he said, according to bystanders. At least one officer apologised to the shop owner, saying he was unable to pay the $14 phone bill because his wallet had been swept away. But the shopkeeper said he was confident the officer would pay up because he was a good customer. The 24 officers aboard the stricken patrol craft yesterday were part of the 300-strong armed forces of the Shenzhen Border Defence, outside Dameisha. Many have been deployed from Beijing, Guangdong and Hunan. The burned ship, Gong Bian D4406, took part in the first joint anti-illegal immigrant operation between Hong Kong and Guangdong marine authorities on May 16. A mainland source said the unit's base - between well-known resorts Dameisha and Xiaomeisha - had been built by a Hong Kong-mainland joint venture as a shipping port. But it was turned into a police base to stem an increase in cross-border smuggling of vehicles, cigarettes, home appliances and livestock as well as illegal immigrants. It is said to be equipped with four patrol craft and several speedboats. Slogans such as 'Determined to sweep away illegal smuggling activities and ensure the prosperity and stability of Hong Kong' stand at the base's main entrance. Meanwhile, fishing boat owners in Sai Kung said Public Security Bureau boats could often be seen in Hong Kong waters. 'We often see PSB boats from the mainland near Tai Long Wan, Basalt Island and the Ninepin islands, both before and after the handover,' said 58-year-old Kwok Pak-fuk.