Search and rescue operations were underway on Tuesday to find victims and survivors from the crashed China Eastern plane that went down a day earlier in the Guangxi Zhuang Autonomous Region.
Over 2,000 people are at the crash site taking part in the operations, reports Xinhua news agency.
Since the site of the crash is located in a mountain forest, the search for the black box relies on both drones and rescue staff.
Zhu Xiaodong, a rescuer with a drone rescue centre, said that it is difficult to carry out rescue work as there are only a few paths leading to the site.
At around 7.30 a.m. on Tuesday, there was light rain at the rescue site.
The local meteorological department forecast that more rain would hit the area from Tuesday to Thursday, which might adversely affect the search efforts.
The China Eastern Airlines Boeing 737 aircraft, which departed from Kunming and was bound for Guangzhou, crashed into a mountainous area near Molang Village in Tengxian County at 2.38 p.m. Monday, causing a mountain fire.
There were 132 people on board -- 123 passengers and nine crew members.
Neither the Chinese government or the airlines have confirmed the exact number of casualties yet, but it is feared that there were no survivors.
Meanwhile the families and friends of those onboard have arrived at Guangzhou's International Airport, the ill-fated aircraft's destination.
Flight MU5735 had been in the air for over an hour and was nearing Guangzhou when it suddenly plummeted from a cruising height.
The Boeing 737-800 plane dropped thousands of metres in three minutes, the BBC reported citing flight tracker data.
According to FlightRadar24, the plane was cruising at 29,100ft, but two minutes and 15 seconds later it was recorded at 9,075ft.
The last sourced information on the flight showed it ended at 2.22 p.m., at an altitude of 3,225ft.
China Eastern Airlines, one of the nation's big three state-owned carriers, has expressed its "deep condolences" to the victims and their families.
It has grounded all its Boeing 737-800s.
