The administration called on Tuesday for all industry entities, including air traffic control, airlines, airports and pilot training institutes, to carry out a thorough, two-week safety inspection to eliminate safety hazards and ensure people's absolute safety.

Along with search and rescue workers, drones have been deployed to the crash site to search for more evidence over an area of nearly 680,000 square meters.

Zhu Xiaodong, a rescuer with a drone rescue center in Guangzhou, said the drones' thermal imaging will help to locate the two black boxes, which record cockpit conversations and flight data.

According to video footage released on Tuesday by China Central Television, search and rescue workers who were marking debris also found charred wallets, train tickets, identification cards and bank cards at the crash site, which is in a forest near Tengxian county's Molang village.

Much of the debris from the aircraft was in small pieces, said Li Chenbin, a technician with China Mobile's Guangxi branch who heard a loud bang echoing across the mountains at around 2:20 pm on Monday.

Li, who was working nearby on the mobile communication network, said, "I then rushed to the site with my colleagues and saw the aircraft debris, much of which was in small pieces. It was scattered all over the mountains. The biggest piece I saw was part of a wing with China Eastern's logo."