Residents walk along a flooded street in Kaihua county, Zhejiang province June 15, 2011. [Photo/Agencies]

BEIJING - China has mobilised troops to help with flood relief and raised its disaster alert to the highest level after days of downpours forced the evacuation of more than half a million people in central and southern provinces.

More than 555,000 people had been evacuated in seven provinces and a municipality after rains in recently drought-stricken areas caused floods and mudslides in the Yangtze River basin.

Chinese media said that as of Thursday evening, floods caused by the most recent four days of rain had resulted in 19 deaths and left seven missing in Anhui, Zhejiang, Jiangxi, Hubei, Hunan, Sichuan and Guizhou provinces and Chongqing municipality.

China raised its disaster alert to the highest level 4, and the government is describing the floods in some areas, such as eastern Zhejiang province's Qianting River area, as the worst since 1955.

Two dikes in the province were breached on Thursday, flooding two towns and 21 villages, Xinhua news agency said.

The official death toll caused by floods and mudslides since June 3 has not been updated since Wednesday, when news reports said at least 105 people had been killed and 65 were missing.

Forecasters warned on Thursday that in the coming days rain could bring fresh danger, including in the southwest. The downpours are not expected to ease until Sunday.

In Jiangxi province in the east, troops helped 122,400 residents move from vulnerable, low-lying areas, the China News Service reported on Thursday.  

In central Hubei province, downpours two days ago triggered a landslide that left six people missing and blocked the Pingdu River, forcing 2,000 residents to flee in case a wall of water burst through the mud and debris.