A huge sinkhole opened up in China, swallowing a section of road and passers-by and leaving at least one person missing, state media reported Wednesday.

At least three people fell into the 30 metre (99 feet) long, 20 metre wide and nine metre deep sinkhole, which appeared during heavy rain in downtown Zhengzhou, in the central province of Henan, the Beijing Youth Daily said, citing witnesses.

An initial investigation showed the collapse might have been caused by water pipes buried under the road breaking up due to the rain, provincial firefighters said in a social media posting.

A man and a woman were brought out by rescuers after the sinkhole opened up but another woman, who was riding an electric bicycle with the man, was swept away by a raging torrent, the Beijing Youth Daily said.

Zhengzhou's city government said it was unclear how many people fell into the hole, the paper added.

Rescuers searching for the missing found three electric bicycles, bags, slippers and some clothes in the cavity on Tuesday.

Sinkholes are not unknown in China, where they are often blamed on construction works and the country's rapid pace of development.

In 2013, five people died when a 10 metre wide sinkhole opened up at the gates of an industrial estate in Shenzhen, which neighbours Hong Kong.