Rain in southern China on Wednesday halted the search for victims and flight information black boxes that could tell why a China Eastern Airlines plane plunged into a mountainside with 132 people on board.
Rain water was filling the depression in the soft soil caused by the impact of the crash, and there were risks of landslides that could endanger rescue workers scouring the difficult, heavily forested terrain, state television reported.
The wet weather was forecast to last for the rest of the week.
Flight MU5735 was en route from the southwestern city of Kunming, capital of Yunnan province, to Guangzhou in Guangdong province bordering Hong Kong, when the Boeing 737-800 jet suddenly plunged from cruising altitude at about the time when it would normally start to descend ahead of its landing.
The cause of the crash in the mountains of Guangxi region is yet to be determined, with aviation authorities warning that their investigation would be very difficult because of the severe damage to the aircraft.
The disaster prompted the aviation regulator to launch a two-week inspection of the sector that will involve checks at all regional air traffic control bureaus, airline companies and flight training institutes to ensure the "absolute" safety.
Since the crash, China Eastern and two subsidiaries have grounded their fleet of more than 200 Boeing 737-800 jets. The last commercial jetliner to crash in mainland China was in 2010, when an Embraer E-190 regional jet flown by Henan Airlines went down.
Having rushed to Guangxi on Monday to oversee the emergency operations, Vice Premier Liu He held a meeting on Tuesday during which officials were urged to go "all out in their search as long as there is a glimmer of hope" for survivors.
Officials were also instructed to release information "in accordance with the principles of timeliness, accuracy, openness and transparency", according to state media reports.
The broader aviation sector was ordered to carry out special checks to prevent any other major accidents.
At the first news conference held by the government late on Tuesday night in Guangxi, an aviation official said the 737-800 jet that crashed had met airworthiness standards before take-off and crew members had been in good health.
The disaster comes as Boeing seeks to rebound from several crises, notably the impact of the coronavirus pandemic on air travel and safety concerns over its 737 MAX model following two deadly crashes.
China Eastern also faces deepening losses and closer regulatory scrutiny following the crash.