TWO children who enjoyed playing with cigarette lighters died when their bedroom was engulfed in flames, an inquest has heard. The cause of the blaze remains a mystery, but evidence suggested the children, aged two and four, started the fire. The jury returned a verdict of death by misadventure. Law Kui-wing, four, and his sister Law Fung-wa, two, had been left with their stepbrother Leung Wai-kei, 15, who was rescued by firemen as smoke and flames enveloped the flat at Tsui Wo House, Tai Wo Estate, Tai Po. The bodies of the two children were found in their bedroom. Wai-kei, a cleaning worker, said he had been left to look after the children, but had fallen asleep. He woke up to find the flat filling with smoke. ''I shouted for help. I was scared,'' he told the inquest. He said he was filling a cooking pot with water to fight the blaze when firemen fought their way in and rescued him. Wai-kei said the children liked to play with lighters. ''My mother told me that the children had been playing with fire on the third day of the Lunar New Year,'' he said. The father, Law Wai-ming, said he scolded the children when they played with cigarette lighters. ''When the children saw me smoke they would hand me the lighter,'' he said. Mr Law added that on one occasion the children had set toilet paper or some newspaper on fire. He said that lighters were normally left on top of the television, although the children could reach them if they climbed. Coroner Rodney Venning said that no evidence had been heard as to what started the fire, but he said a verdict of misadventure could be returned if the jury believed that the children started the fire which led to their deaths. The cause of death was inhalation of fumes.