The shooting incident involving a Romanian cargo ship just outside Hongkong waters on Sunday is the latest in a worrying spate of piracy in the vicinity. The 33,600-tonne Birlad was fired upon by three fishing vessels which had approached and circled it about 78 nautical miles east of Hongkong. Although details are sketchy, the Birlad did not succumb to the assailants' plan. Instead, it carried on course, ignoring radio messages to allow the intruders to board and after a two-hour chase, gave up. Fortunately, no one was injured. Mr Po So-ha was not so lucky. The Tuen Mun boat master was killed a week ago by pirates who did succeed in boarding his vessel and gunning him down before escaping with cash and valuables. On Saturday, three Vietnamese vessels disappeared just after they reported being chased into Hongkong waters by Chinese security officers. Incidents such as these are worrying because they harm the territory's reputation as one of the world's biggest container ports and as an international trading centre. It is incredulous that in this modern age of high technology, vessels conducting legitimate business in the waters around Hongkong and the region should be vulnerable to acts of villainy that belong to another buccaneering era. No doubt the Birlad was able to fend off its attackers because it heeded warnings issued by the Marine Department two months ago to speed up and sail on in any piracy attack. However, smaller boats such as those steered by Mr Po are largely helpless against marauding high-powered vessels and their well-armed occupants. At this point it is not certain that the Birlad's assailants were indeed pirates. They could equally have been renegade members of the public security forces who have been known to board vessels and seize cargo. Last year, more than 15 ships leaving Hongkong for the Vietnamese port of Hon Gai were stopped and boarded by armed Chinese security officers and their crews tied up and cargoes confiscated. Even though eight men were arrested in the attack that killed Mr Po, the success rate for bringing to justice the many others responsible for terrorism on the high seas remains disturbingly low. Every time piracy is committed or attempted, howls of protest are raised by vested shipping concerns and calls made for increased regional co-operation. With two out of three acts of piracy worldwide taking place in the waters around Hongkong, the Strait of Malacca or the Java Sea, responsibility for policing the South China Sea must be shared with other countries in the region. China especially must be willing to step up its co-operation with Hongkong in policing the waters that border both territories. The need for better co-operation between Hongkong and China has partially been addressed with Beijing's posting of liaison officers here to allay local concern over the threat to law and order from criminals coming across the border. Although the intention of the officers had been to improve cross-border liaison, little is known about their work or whether they have been able to yield any meaningful results. The local New China News Agency declines to allow them to discuss their work and as a result, an aura of secrecy is built up around them. Such secrecy can only raise doubts about whether they are indeed helping to bring those who commit crimes and acts of piracy to justice. The number of incursions by Chinese security vessels into Hongkong waters and the growing incidents of piracy suggest more needs to be done if the territory aims to uphold its reputation as a leading shipping port and international centre for trade.