Some Hong Kong tour agencies have suspended hot-air balloon trips in Egypt and elsewhere after yesterday's fatal accident in Luxor, while others are reviewing their activities. Besides Kuoni, which organised the tour on which the nine Hongkongers died, EGL Tours has suspended balloon trips in destinations including Turkey and Australia. But EGL said it could not prevent individual holidaymakers from taking part in such activities at their own risk. Hong Thai, which currently has one tour group in Egypt, also cancelled balloon rides in Luxor and is reviewing hot-air balloon activities in other international destinations. Other agencies say they do not know when and under what conditions balloon trips at destinations around the world will resume. All eight balloon operators in Luxor are understood to have suspended activities. Steve Huen Kwok-chuen, who operates EGL, said the company cancelled balloon trips in Egypt five years ago as the operator it worked with had no insurance. "At that time, the operator failed to secure insurance coverage," Huen said. "An insurance policy is a proof that it has met safety standards." He said, however, that trips with the operator resumed three years ago when it secured insurance for its operations. Huen said EGL would assess the track record of a balloon operator, its facilities and the experience of its pilots before considering entering into a partnership. But Ronnie Ho Pak-ting, chairman of Jetour, said his company had decided not to suspend balloon trips as the cause of the accident was still not fully known. "The question is whether hot-air ballooning is really that dangerous. There are lots of balloons rising up every day … just like so many cars run in the street too," he said. He said the tour agency had no expertise in assessing whether a balloon operator was reliable and safe or not. "We have to rely on the information supplied by the local operator," Ho said. Dr Liu Chun-ho, an assistant professor of mechanical engineering at the University of Hong Kong, said the accident could have been caused by the pilot overheating the balloon. Poor maintenance may also have contributed to the tragedy, Ho said. "Most probably, the parts were aged or had a lack of maintenance," he said. Sightseeing balloons carry tourists every day and operators usually conform to standard safety measures, he said. In January last year, a hot-air balloon carrying 11 people burned up after hitting power lines near Carterton, New Zealand. All on board were killed. Four Dutch tourists were killed in the scenic town of Yangshuo in Guangxi in October 2009. Their hot-air balloon burst into flames and plummeted 150 metres to the ground after its pilots lost control. Also in Luxor, in April 2009, 16 tourists from different countries were injured when their hot air balloon struck a mobile phone transmission tower near Gourna village on the west bank of the Nile and crashed. Yesterday's tragedy was the deadliest ballooning accident in more than 20 years. Similar incidents include: DISASTER AFLOAT Slovenia On August 23 last year, six people, including a child, were killed when a balloon caught fire and crashed near Ljubljana, after the pilot lost control in strong winds and hit a tree. New Zealand On January 7 last year, 11 people were killed when their balloon hit a power line and burst into flames during a pleasure flight near Carterton, north of Wellington. China On October 14, 2009, four Dutch tourists died when their balloon caught fire and crashed in Yangshuo, Guangxi. France On August 26, 2001, six people, including a child, were killed when their balloon touched a power line in Verrens-Arvey, southeastern France. Germany On June 17, 1999, four passengers died when their balloon hit a power line near Ibbenbüren, western Germany. On January 16, 1994, an accident in which a balloon burst into flames during landing near Mosbach, southwestern Germany, killed three people. Switzerland On January 31, 1996, five people were killed when strong winds dashed their balloon into a mountainside at a height of 2,400 metres in the Bernese Alps. United States On August 8, 1993, six people were killed when a balloon hit a power line near Aspen, Colorado. The impact tore off the basket and sent it plummeting 30 metres to the ground. Austria On October 6, 1990, four people were killed in a balloon crash in Gänserndorf, near Vienna. Agence France-Presse