Carmakers and dealers from across the country are donating millions of yuan and offering rescue services to local residents and car owners suffering from the deluge caused by continuous heavy rainfall in Central China's Henan province.

Local authorities said the torrential rains had affected more than 3 million people by Thursday. A total of 51 people died in Zhengzhou, capital of Henan province, by Friday noon, with direct economic looses estimated to reach 65.5 billion yuan ($10.11 billion).

Donations from companies including Nio, Geely and Mercedes-Benz totaled more than 800 million yuan by Friday, with the list of companies still growing.

Chinese electric car startups were the first among carmakers to announce donations. Nio, Xpeng and Li Auto made their announcements on Wednesday afternoon, with a combined donation of 40 million yuan.

"The heavy rainfall and its damage caused in Zhengzhou and other parts of Henan concern every one of us. We would like to send our sympathies to them," said Nio CEO William Li.

Other companies soon followed. In the late afternoon of Wednesday, BYD, Geely and Great Wall Motors made public their donations of money and disaster relief goods, including drones.

The three leading private carmakers' combined donation totaled 70 million yuan. BYD is opening all its dealerships in Zhengzhou, capital city of Henan province, to local residents and car owners for urgent needs.

On Wednesday, Mercedes-Benz announced a donation of 10 million yuan to Henan. The German premium car brand said it has also coordinated vehicles in neighboring provinces and cities to offer rescue services for its dealers and car owners in Henan.

State-owned Chery Automobile announced on Thursday morning that it will donate 35 million yuan to rain-affected cities in Henan province.

On the same day, Sino-German joint venture FAW-Volkswagen decided to donate 25 million yuan.

Of the money, 10 million will be used for disaster relief and reconstruction efforts while 15 million will be spent on the urgent rescue and repair of Jetta, Volkswagen and Audi vehicles, said the carmaker.

The joint venture, like many others, started to offer rescue services before its donation was made.

Local Chinese companies including SAIC Maxus, WM and Nio are helping appease the victims in Henan province by helping them contact insurance companies to cover damages caused to their vehicles.

Joint ventures including Dongfeng Nissan and Dongfeng Peugeot are offering rescue services to local residents and car owners.

But Dongfeng Peugeot's hotline staff said it was not aware of the move and had no rescue vehicles or food when it was contacted by locals on late Wednesday.

The Sino-French joint venture soon apologized on its Sina Weibo account for not being fully prepared. It said a contingent team and four dealerships in Zhengzhou are in place, saving 106 vehicles stranded in water by the early morning of Thursday.