The road collapsed in the wee hours of Wednesday, the first day of the five-day May Day holiday break as millions in the country travel.

The collapse, triggered by heavy rain, occurred at around 2:10 a.m. on the Meizhou-Dabu Expressway, Xinhua news agency reported, adding that 17.9 meters (58.7 feet) of the road gave way and caused 23 vehicles to plunge. Another 30 people sustained injuries, it said.

Meizhou is one of the areas in southern China’s Guangdong that has been badly hit by heavy rain and hail since late April which set off dangerous mudslides, inundated homes and destroyed bridges.

Meizhou officials told a press conference on Thursday livestreamed on state broadcaster CCTV that 577 relief personnel and more than 80 rescue vehicles and equipment had been dispatched to the site but rescue work proved difficult as some vehicles were buried deep in the mud after their fall.

Video from state media showed a twisted metal guardrail and a big hole in the path of the forested green area where the collapse happened. Rescue personnel with cranes and excavators as well as a few damaged cars could also be seen.

Some vehicles fell and caught fire, according to social media accounts in China. A driver of a vehicle said in a video posted on Weibo he saw a crack in the road in front of him and mistook it for a puddle, but sped off before the road collapsed.

President Xi Jinping called for the utmost efforts to save lives and eliminate danger as rainy weather continued in the region, according to a Xinhua report.

Task forces from the central and local governments have been dispatched for the rescue work, the report added.

(Reporting by Chen Aizhu and Ma Rong; Editing by Muralikumar Anantharaman)