Aided by boatmen, residents make their way around streets flooded by heavy rain in Rongshui Miao autonomous county in the Guangxi Zhuang autonomous region on Sunday.Long Linzhi / For China Daily

As a heat wave in northern China continues, more rain is expected along the Yangtze River, which flooded for the first time this year on Saturday.

China's national weather observatory issued a yellow alert for the third consecutive day on Sunday, the second-lowest in a four-tier weather warning system, for rainstorms in the southern part of the country.

The southern regions have seen six heavy downpours. June precipitation in central Hunan province, for example, was double that of the same month last year.

Days of torrential rains in Hunan raised the water level of the Xiangjiang River, a major tributary of the Yangtze, beyond its record flood level on Sunday morning. The water level at Changsha, Hunan, reached 39.44 meters at 3pm - the previous record, set by a massive flood in 1998, was 39.18 meters .

Already at 3.44 meters above the warning, the water level is expected to continue to rise as heavy rains are forecast for upstream regions over the next few days. Water at Dongting Lake and in several major rivers in Hunan has also risen above warning levels.

Rain began to batter Hunan on June 22, and the ensuing floods have forced the evacuation of 577,100 people. Nearly 406,000 hectares of crops have been damaged, and 9,861 houses have been destroyed, according to the provincial meteorological service.

A rain-triggered landslide in Ningxiang county led to the deaths of five people. Four people remained missing.

Many parts of the county received more than 200 millimeters of precipitation within 24 hours, with flooding disrupting traffic and telecommunications, while raising water levels in reservoirs and rivers above warning levels.

A search and rescue operation is underway.

"The water is rising, and my house is in danger of being submerged. I was relieved when I saw a rescue boat coming," said Zhou Changsong, who was evacuated on Saturday afternoon from Chenxi county, Hunan.

In the neighboring Guangxi Zhuang autonomous region, flooding disrupted railway services, with 45 trains canceled, forced to return or detoured.

The State Flood Control and Drought Relief Headquarters has ordered the Three Gorges Reservoir on the Yangtze to reduce the flow of discharge to 18,000 cubic meters per second to relieve the flood pressure downstream, and launched a Grade III emergency response plan, the second-lowest of the four-tier national response system.

In Jiangxi province, which neighbors Hunan, flooding was blamed for seven deaths. Two people remain missing. About 440,000 people had been evacuated as of Saturday.

Contact the writers at houliqiang@chinadaily.com.cn

Xinhua contributed to this story.