Rescue efforts are underway in the city of Qinzhou, Guangxi Zhuang autonomous region, after record-breaking rain triggered severe flooding, forcing the evacuation of more than 800 residents, according to local officials.

Emergency teams have been deployed to carry out evacuations and drainage work as authorities warned of further heavy rainfall and the risk of renewed flooding.

According to China Weather Network, Qinzhou recorded 271.1 millimeters of rainfall between 8 am on Sunday and 8 am on Monday, marking the highest daily total for April and the earliest such extreme event on record in the city.

Forecasters said the current rain belt is expected to shift eastward and weaken on Wednesday.

Localized heavy rain, thunderstorms and strong convective weather in the city may persist through Wednesday morning, with continued risks of urban waterlogging and secondary disasters, according to the city's flood control and drought relief headquarters.

By Tuesday, floodwaters in the main urban area had receded, while drainage operations continued in some residential compounds and underground garages.

Pumping at nine severely flooded residential garages was expected to conclude later in the day, followed by gradual restoration of water and electricity supplies, according to the headquarters.

Rescue teams from emergency services, fire departments and the People's Armed Police Force were deployed to assist with evacuation efforts.

In one case, three elderly residents and two children were rescued from a second-floor unit in a flooded residential building, where water had risen to chest level.

"The current was very strong as we approached the building," said Zhang Zhongyang, a squad leader with the rescue team. "We could hear them calling for help, so we moved faster."

Community workers also assisted evacuations and recovery. In Wenfeng subdistrict, workers waded through floodwaters to help elderly residents, while in Dongfeng community, teams helped drain a low-income resident's home and recover belongings, Guangxi Daily reported.

Xin Xin, a meteorological analyst, said the rare late-April rainfall was driven by a "training effect", in which successive storm cells repeatedly moved over the same area.

Strong low-level southerly winds met coastal convergence near Guangxi, triggering new storms that kept heavy rain concentrated over Qinzhou, Xin added.