NANNING -- Rescue work continued on Tuesday after a passenger plane with 132 people aboard crashed in South China's Guangxi Zhuang autonomous region Monday afternoon.

Over 2,000 people have been sent to the site as part of the rescue efforts.

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 center in Guangzhou, capital of South China's Guangdong province and also the destination of the plane, said at the site that it is difficult to carry out rescue work as there are only a few paths leading to the site.

Experts from the public security department and the Civil Aviation Administration of China are entering the main crash site to search for physical evidence, confirm the identity of the missing persons and find out the possible cause of the accident. Some personal belongings of the passengers have been collected and numbered.

Drones have been deployed on the site to search for more evidence in an area of nearly 680,000 square meters. Their thermal imaging function will help locate the black box.

At around 7:30 am on Tuesday, light rain began to fall over 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.

On Tuesday afternoon, Xinhua reporters spotted around six excavators and nearly 50 workers scrambling to clear a passage to the site for rescue crew and necessary machinery.

"We need to complete all preparations prior to the rain, and the initial objective is to gain entry to the site by approximately 8 pm Tuesday," said Guo Zhaoliang, in charge of the route construction.

The China Eastern Airlines Boeing 737 aircraft, which departed from Kunming and was bound for Guangzhou, crashed into a mountainous area in Tengxian county in Guangxi at 2:38 pm Monday, causing a mountain fire.