All China Eastern Yunnan Airlines pilots who fly Yunnan routes have been temporarily suspended from service after they went on strike on Monday and left more than 1,000 passengers stranded. An industry source said the pilots had been 'playing a prank' on the company to protest against 'unfair treatment'. The company, formerly China Yunnan Airlines, was taken over by China Eastern Airlines in October 2002 and its pilots were allowed to fly only domestic routes, resulting in lower pay. 'Pilots are paid according to their flying hours,' the source said. 'Those who fly within Yunnan travel for only about 40 minutes, while international routes take hours. Because of differences in how they collect payment and pay taxes, pilots on domestic routes also pay tens of thousands of yuan more in tax.' Almost all the pilots flying Yunnan routes took part in the partial strike. The pilots flew the aircraft to the destination airports but did not land, citing bad weather, and then returned to the province. 'The company could not really punish the pilots because they had the final say on whether to land for safety reasons,' the source said. He said company managers who used to be pilots took over the Yunnan routes yesterday to prevent further strikes. The company was holding an emergency meeting last night. Yunnan Information Daily reported yesterday that more than 1,000 passengers were stranded at Kunming airport after 14 provincial flights returned there without landing at their destinations. A passenger bound for Lijiang , identified only by his family name Wu, said the passengers were informed that they would be landing in 15 minutes, but returned to Kunming after circling over Lijiang airport twice. The passengers were told the aborted landing was due to bad weather, but flights from other airlines had landed successfully, Mr Wu said. Another passenger, surnamed Du, said his flight to Puer arrived at the destination but also returned to Kunming without landing. 'When I returned to the check-in counter in Kunming, I was surprised to find the counters were crowded with passengers with similar experiences,' Mr Du said. 'I checked and found the flights involved not only those to Puer but also to Dali , Lijiang , Mangshi , Lincang and Zhaotong .' The report said an anonymous open letter was posted in the office building, which called on all pilots of the Yunnan company to 'wake up' to the fact that they were being underpaid, and some inspections targeting pilots were 'causing enormous damage to the pilots' self-respect'. The letter also questioned the fairness of the company in demanding compensation of 12.57 million yuan from Zheng Zhihong , a former pilot who wanted to quit. He eventually paid the company 1.3 million after arbitration. A spokesman for the China Eastern Group said it had no knowledge of the strike.