Rescuers are still working around the clock in the mountainous area of South China's Guangxi Zhuang autonomous region where a passenger plane with 132 people aboard crashed, local officials said on Tuesday night.

A total of 538 rescue workers with 119 fire trucks from Guangxi rushed to the site of the crash immediately after the accident happened on Monday afternoon, with lighting equipment, tents and epidemic prevention materials.

Rescue staff from Guangdong province and forest fire control officers were also dispatched to the site to help, said Zheng Xi, head of the Guangxi regional fire and rescue corp.

"Rescuers quickly started searching at the site, but given that the area is located in a mountain forest with narrow roads and gullies, it's difficult to carry out the rescue work," he said at a news briefing on Tuesday night. "The search within 20 kilometers of the crash site has also begun."

China Eastern Airlines flight MU5735 left Kunming, capital of Yunnan province, at 1:11pm, bound for Guangzhou, capital of Guangdong province. Air traffic controllers lost track of the plane over Wuzhou, Guangxi. The plane was carrying 123 passengers and nine crew members.

Zheng said when the first rescue force from Tengxian county of Wuzhou arrived at the accident site at 3:50pm on Monday, they found some wreckage and there was a strong smell of fuel. So far, no survivors have been found.

Sun Shiying, chairman of the airline's Yunnan branch, said on Tuesday night that the company has managed to contact family members of all passengers, in many locations around the country.

"We've established centers to offer aid for those relatives in Kunming, Guangzhou and Wuzhou. More than 160 experts are there for assistance," he said.