Two suspected killers are on the run after two men died in an arson attack on a Tsing Yi flat early yesterday. The victims, Chan Chi-sing, 20, and Cheuk Oi-ming, 44, were sleeping in a friend's flat on the 16th floor of Ching Yung House, Cheung Ching Estate, when it was set alight at 4.30am. Their friend was not in Hong Kong at the time. A security gate on the flat was locked but the door was open. 'Preliminary investigations show that a metal can containing three to four litres of inflammable liquid was hurled into the unit before it was set alight,' Chief Inspector Tsang Fan-kwong, of the New Territories South regional crime unit, said. 'The blaze broke out in the doorway and blocked the exit. The two victims apparently ran into the toilet and hid inside to wait for help.' Scores of residents fled downstairs before fire fighters and police arrived. Fire fighters broke open the security gate and doused the flat, which was engulfed in flames. 'The two men were found unconscious in the toilet about 10 minutes after firemen arrived, their faces and clothes were blackened and they had lost consciousness,' senior Tsing Yi fire station officer Chow Chiu-leung said. They were taken to Princess Margaret Hospital, where they were declared dead. The blaze was put out at about 5am. The attack has been classified as arson, and homicide officers from New Territories South regional crime unit are investigating. Officers were hunting for two men who were seen fleeing the building. In a separate case, an eight-year-old girl, her brother, 10, their mother, 38, 70-year-old grandmother and a domestic helper, 24, were overcome by smoke when a blaze broke out in their first-floor flat in Belvedere Garden, Tsuen Wan, at about 12.30am. They were admitted to Yan Chai Hospital and were all in either a stable or satisfactory condition last night. The blaze was extinguished by about 1am.