More than 70 passengers staged an 18-hour sit in on a Hong Kong Airlines plane after their flight to Shanghai was cancelled late on Friday night. It was the second Hong Kong sit-in the airline had faced in two months, after 31 passengers refused to leave a flight from Bali after an eight-hour delay. In the latest incident, some 200 passengers were aboard flight 234, which had been due to depart at 9pm on Friday, and most accepted an offer of a transfer to a later flight. Watch: Hong Kong Airlines passengers stage 18-hour sit-in on plane But some refused and complained about the arrangements. They said they had been offered only HK$200 in compensation and not offered accommodation. HSBC customer forced to make 16,000-kilometre trip to access account after bank blunder The passengers are understood to have left the plane at about 3pm yesterday after the airline increased its compensation offer. In a video uploaded to the internet, passengers complained that, after refusing to leave the plane, they had been left without food and water. People's Daily quoted passengers as saying the air conditioning onboard had been turned off during their protest. One passenger told People's Daily their protest was "not about the money", but the airline's attitude, and that it should offer them "a reasonable amount of financial compensation". People's Daily showed letters sent to the passengers promising HK$800 each in compensation and an apology. Police were called in just before 4am. An airline spokeswoman said the delay was due to mainland air traffic control. All passengers had left for Shanghai by yesterday evening. In November 2011, 21 passengers refused to leave a Hong Kong Airlines flight after a nine-hour delay in leaving Singapore. In 2012, 17 passengers refused to leave a flight from Shanghai after an 18-hour delay due to fog.