Photo: A screenshot of the construction site from Sina Weibo

More than 1,100 rescue workers and nearly 200 emergency response vehicles were deployed on Monday, to search for three people whose vehicles fell into a sinkhole on Sunday near a construction site of a new subway line in the capital of South China's Guangdong Province, local government said.

The sinkhole appeared Sunday morning and the subway operator, Guangzhou Metro, said steel casings designed to hold back further erosion have been installed in the sinkhole. It didn't say if they had found any sign of the missing people or their vehicles, one of which was a city garbage truck, the other was reported to be a motorcycle. 

The subway is being built near a highway overpass which was closed to traffic until early Monday morning.

The sinkhole appeared at 9:28 am Sunday near a construction site for a subway station on the city's new Line 11 and rescue work immediately began after three people were reported to have fallen into the meters-deep hole.

According to Guangzhou Metro's post on its official Sina Weibo account on Sunday late Sunday night, the company said a garbage truck and an electric motorbike fell into the sinkhole, trapping the truck driver, a passenger and a motorcyclist.

No construction workers were hurt, the company post read. "The accident did not affect the currently running subway lines, and the cause of the incident is under investigation." 

The truck driver and passenger were father and son, surnamed Shi. The younger man had become a father just a month ago, Shanghai-based news website thepaper.cn reported on Monday.

The identity of the motorcyclist has so far not been reported.