Some of the victims of a fire at a Shantou hotel that claimed 31 lives leapt to their deaths as flames engulfed the four-storey building, witnesses and doctors said yesterday. They said some windows and doors at the Huanan Hotel were locked, making it difficult for many people trying to escape. Friday's blaze - the worst fire in Guangdong for more than a decade - prompted Governor Huang Huahua to order a province-wide overhaul of work safety. The cause of the fire is still under investigation. Firefighters found several LPG cylinders in the hotel, but it was unclear if they sparked the blaze. Four of 15 people injured in the fire were in critical condition and receiving emergency treatment at the city's Central Hospital, Xinhua said. The blaze broke out just after noon on Friday on the second floor of the hotel and immediately devoured the four-storey building. The hotel is thought to be owned by a Hong Kong businessman and managed by local people. The blaze burned for more than three hours and was 'the most serious fire accident in the province since 1994', Xinhua said. Witnesses said they first saw smoke emerging from karaoke rooms on the second floor of the hotel and thick black smoke soon engulfed the entire building. 'I was suffering a huge headache from the smoke so I decided to get out through a window,' one survivor said from his hospital bed. 'My headache has gone but my arms and legs are broken.' A doctor told the Southern Metropolis News he treated five victims who had jumped from windows to escape the flames and who all later died. Mr Huang cut short a work tour to southwestern Yunnan province and rushed to the scene of the fire on Friday afternoon. 'The fire on June 10 was the most fatal one in our province in recent years ... this lesson of blood serves as a reminder that we should do everything to prevent loopholes in work conditions, and in any case, we cannot get complacent over work safety issues ... we should always be on alert,' Governor Huang said. 'All work safety conditions in the province should be checked and rechecked.' He vowed to set up an investigation team to immediately look into the accident and assign responsibility for the disaster. The State Administration of Work Safety, the national industrial-accidents watchdog, sent a taskforce to Guangdong to co-ordinate inspection work.