The death toll in highway collapse in China's Guangdong province has risen to 36, as the emergency team continues to make efforts to recover cars from the spot, Al Jazeera reported.

As of 5:30 am (local time) on May 2, 36 people have died and 30 people have been injured after part of a highway collapsed on Wednesday, Al Jazeera reported, citing state news agency Xinhua. As per the report, the injured people were not in life-threatening condition.

The road collapsed in the early hours of Wednesday morning as the May holidays started in China. It is traditionally one of the busiest times of the year on the roads.

Aerial pictures showed one side of the S12 highway between Meizhou City and Dabu County had collapsed, causing mud to cascade down the steep and forested hillside. A 17.9-metre (58.7-foot) stretch of the road collapsed, with 23 vehicles found in the muddy pit.

The incident was a "natural geological disaster" that occurred under the impact of continuous heavy rain. Several people who witnessed the incident said that they heard "sounds of cars falling" after "a heavy explosion."

One person said, "We stopped and got out of the car to check and had no idea the road had collapsed," Al Jazeera reported, citing Guizhou Evening News. Following the incident, the highway was closed in both directions and some 500 emergency personnel including firefighters and mine rescue experts were deployed to the spot to help with the rescue operation.

Photos from the spot showed a giant crane pulling the damaged cars from the mud, with excavators on standby. Rescuers were also searching with dogs and life-detecting devices.

The search efforts were affected by rain as well as gravel and soil movement at the site of the incident, posing some risk to the workers, according to a fire department official, Al Jazeera reported, citing state media.

The highway collapse incident is the latest in a series of disasters related to extreme weather events in Guangdong in recent weeks. Heavy rains in April have resulted in floods in various parts of Guangdong that claimed the lives of four people and forced the evacuation of more than 100,000 residents.

Last week, five people were killed after a tornado tore through Guangzhou. The rainfall has been more than it would have been normally expected this time of the year and has been linked to climate change.