China's aviation regulator has ordered Chinese airlines to suspend their Boeing 737 Max aircraft, media outlet Caijing reported on Monday, following a deadly crash of a 737 MAX 8 operated by Ethiopian Airlines.An Ethiopian Airlines 737 Max 8 bound for Nairobi crashed minutes after take-off on Sunday, killing all 157 people on board.It was the second crash of the 737 MAX, the latest version of Boeing's workhorse narrowbody jet that first entered service in 2017.Caijing, citing industry sources familiar with the matter, said Chinese airlines, which operate some 60 such airplanes, had received orders from the Civil Aviation Administration of China (CAAC) and halted their use on Sunday.The CAAC said it would issue a statement on its website regarding the 737 MAX soon. Media said its Chinese airlines operates more than 90 of the planes.A source at one Chinese operator of 737 MAX jets told Reuters the airline had stopped operations after getting a notice early on Monday. The source was not authorised to speak to media about the matter.A Boeing spokesman declined to comment. The CAAC could not be immediately reached for comment.A U.S. official told Reuters the United States was unsure of what information China was acting on.The U.S. official, speaking on condition of anonymity due to the sensitivity of the matter, said there were no plans to follow suit given the 737 MAX had a stellar safety record in the United States and there was a lack of information about the cause of the Ethiopian crash.In October, a 737 MAX flown by Indonesian budget carrier Lion Air flying from Jakarta on a domestic flight crashed 13 minutes after take-off, killing all 189 passengers and crew on board.The cause of that crash is still being investigated. A preliminary report issued in November, before the cockpit voice recorder was recovered, focused on airline maintenance and training and the response of a Boeing anti-stall system to a recently replaced sensor but did not give a reason for the crash.Caijing, a state-run news outlet that covers finance and economics, said many flights scheduled to use 737 Max planes would instead use the 737-800 models.China Business News also reported on its website the 737 Max suspension, saying the regulators' order had been issued orally.According to flight tracking website FlightRadar24 there were no Boeing 737 Max 8 planes flying over China as of 0043 GMT on Monday.Most of Air China Ltd's 737 MAX fleet of 15 jets landed on Sunday evening, with the exception of two that landed on Monday morning from international destinations, according to data on FlightRadar24.It did not list any upcoming scheduled flights for the planes, nor did China Southern Airlines Co, which also has its fleet on the ground.China Eastern Airlines Corp Ltd four 737 MAX jets landed on Sunday evening and no further flights were scheduled until Tuesday, FlightRadar24 data showed.Cayman Airways has grounded both of its new 737 MAX 8 jets until more information was received, the Cayman Islands airline said in a statement on its website.Fiji Airways said it had followed a comprehensive induction process for its new Boeing 737 MAX 8 aircraft and it had full confidence in the airworthiness of its fleet."We continue to ensure that our maintenance and training programme for pilots and engineers meets the highest safety standards," the airline said.Singapore Airlines Ltd, whose regional arm SilkAir operates the 737 MAX, said it was monitoring the situation closely, without providing further details.