Regional vegetable prices rise by 40% as rains flood more that 1m acres of farmland and affect lives of 5.7 million people

Food prices are expected to rise steeply in China after flooding inundated more than 1 million acres of farmland in eastern provinces, killing at least 100 people and displacing hundreds of thousands more.

Weeks of torrential rain in Zhejiang province in the Yangtze delta have caused nearly 6bn yuan (£575m) of damage, reducing vegetable production by 20% and pushing prices in the provincial capital of Hangzhou up by as much as 40%, Xinhua news agency said.

The rains have forced almost 1,000 businesses to suspend operations and affected the lives of 5.7 million people, China's official news agency said in a brief report. More than 7,000 homes had collapsed or were otherwise damaged. The rains are expected to continue for two days, stretching from the financial hub of Shanghai in the east to rural Yunnan in the far south-west.

Farmers quoted by Xinhua reported shortages of fruit and grains. Prices for green vegetables were up 40%, the agency said, adding pressure to inflation already at a three-year high of 5.5%.

Villagers on the outskirts of Zhuji in Zhejiang returned to their homes on Sunday as floodwaters receded. Two towns were inundated and thousands of people were evacuated after the breach of two dykes on Thursday. China has mobilised troops to rescue stricken farmers and distribute food, but some villagers said more could have been done to prevent the flooding.

"When the flooding first started, the breach was not that huge. We could have easily fixed it," said Shou Qiongdan, 22. "But the government did not do anything. None of the local officials tried to salvage the situation. That's why we have such huge economic losses and so many people being affected by the flooding."

In neighbouring Jiangsu province, more than 20cm of rain fell on Suzhou city on Friday night, and the Yangtze river and its tributaries burst their banks, affecting up to 3 million people.