A resident of Haining, Zhejiang province, holds some of the giant hailstones that fell on the town yesterday.
The Ministry of Land and Resources yesterday ordered its provincial offices to prepare for possible natural disasters triggered by extreme weather conditions.
Over the past two days, several southern and eastern provinces have been hit by hail- and thunderstorms, sparking concern that this year's flood season might start earlier than expected.
Hunan and Hubei provinces in the south of the country and Jiangsu, Jiangxi and Zhejiang provinces in the east have all been hit by storms and heavy winds.
In Hubei, at least eight people have been killed, while hundreds of thousands have been affected.
Yuan Xiaosu, vice-minister of land and resources, said during a televised meeting yesterday: "Heavy rainfall could lead to geological disasters, such as mudflows and landslides.
"Local land departments should send work teams to areas where heavy rains are forecast in order to identify potential dangers and set up facilities to deal with emergencies as they happen."
Once the national emergency response system is finalized in 2010, experts from the ministry will be able to join on-the-spot crews, provide remote assistance and help with disaster-relief work, he said.