Heavy fog caused widespread power failures in Liaoning province yesterday. Fog blanketed Shenyang - a city of six million and an important industrial base in northeastern China - throughout the morning, seriously delaying flights and trains. Factories and mines came to a standstill and newspapers were left half-printed. The situation improved when the fog dispersed in the afternoon, and electricity was restored to most areas by early evening. Officials said the moist air caused short-circuits in high-voltage power cables and substations. 'A large number of the circuits broke down and three attempts to restart supply failed,' Xinhua quoted Shenyang Power Supply Bureau officials as saying. Officials described yesterday's power failure as the most serious the province has seen. Three Liaoning power plants - Tieling, Qinghe and Huanggu - went out of service. Two others that just serve Shenyang - Shenyang Power Plant and Shenyang Thermopower Plant - also broke down. In addition to Liaoyang, the outages affected the cities of Tieling and Fushun, although the problems there were not as serious. Officials said more than 70 per cent of Shenyang city - with the exception of Heping district in the downtown area - suffered power failure, with industrial and suburban areas affected most. Morning traffic almost ground to a halt. The airport closed down for six hours with 20 flights delayed. Train services were suspended until after midday. More than 1,200 traffic police were sent to direct traffic across the city as more than one-third of traffic lights were out. But police efforts did not stop a pile-up on the Shenyang-Shanhaiguan Highway in which three people were killed and 24 injured. The highway, which links the city to other provinces, was paralysed for six hours. Even the city's newspaper, the Shenyang Daily fell victim to the power failure. Only a small number of copies could be printed. Shenyang residents said the heavy fog was unusual although the downtown area only suffered a short blackout. 'It was fortunate that the power failure happened in the early morning and most of the shops could stay open [even without electricity]. But my home had no power for two hours in the morning,' said a hotel worker in Shenyang. Another resident said: 'The fog was so thick this morning. It was like the whole city was covered by a black blanket and cars could hardly move even if they had their headlights on.' The city Government called an emergency meeting at 8am to discuss contingency measures. Xinhua said no estimate of economic losses was available as yet.