Householders were warned last night not to leave rice cookers plugged in, after one was blamed by a witness for the fatal Shamshuipo blaze. The Consumer Council, which found last year that 17 of 23 rice cookers failed safety tests, said that while unsafe appliances were illegal, the only way to guarantee safety was to pull the plug out after using a cooker. Spokesman Kenneth So Wai-sang said a product safety law enacted after the tests were carried out should mean that no dangerous cookers are on shop shelves or in people's homes. But he said consumers did not always respond to product recalls and there was a chance dangerous items were still being used. Fire Services Department spokesman Francis Ma Kam-biu said nothing could be ruled out yet as the cause of yesterday's blaze. 'According to one of the witnesses, the fire started from a rice cooker, but we cannot confirm that as we are waiting for other witnesses and the government chemist,' he said. 'The cause of the fire is still under investigation.' But a spokeswoman for the Electrical and Mechanical Services Department said officers had been to the scene and ruled out the rice cooker as the source of the fire.