Massive floods in central China caused by record-breaking rainfall have left 12 dead and more than 100,000 people evacuated from their homes.

More than a dozen cities in Henan province, including its provincial capital Zhengzhou, are affected.

Footage circulating online show people wading in chest-high levels of water on roads and train stations.

President Xi Jinping said on Wednesday the "flood prevention situation was very severe" and at a "critical stage".

He added that the floods had already resulted in "significant loss of life and damage to property", and instructed all departments to prioritise "the safety of people and their property", according to state news agency Xinhua.

Henan province, home to about 94 million people, has issued its highest level of weather warning. Local authorities called the floods a "once in 100 years" event.

The rain began over the weekend, with storms intensifying on Tuesday.

By Tuesday night, Zhengzhou and other places in Henan province saw widespread flooding. There were reports online of people swept away by fast-moving floodwaters, and cars and debris drifting down submerged streets.

Several dams and reservoirs have breached warning levels, and soldiers have been mobilised to divert rivers which have burst their banks. Flights and train operations in many parts of Henan have also been suspended.