BEIJING, July 28 (Xinhua) -- Authorities in Beijing issued alerts for rainstorms and flooding on Monday as parts of the Chinese capital brace for torrential rainfall, raising concerns over flash floods and landslides in mountainous areas.

The city's meteorological service upgraded the rainstorm warning from orange to red, the highest in China's four-tier alert system, at Monday noon time, forecasting widespread heavy rain from 8 p.m. until Tuesday morning. Most areas in the city are expected to receive over 150 mm of rainfall within six hours, with some locations seeing more than 300 mm.

The meteorological department has issued a high-risk warning for flash floods, mudslides and landslides in mountainous and hilly regions, while low-lying areas may face severe waterlogging. Residents have been urged to take necessary precautions.

Since July 26, consecutive rainfall influenced by warm, moist air from the edge of the subtropical high has affected Beijing's Miyun, Huairou and Yanqing districts. The northwest part of Miyun, in the northeast of Beijing, experienced particularly heavy rain, with totals exceeding 300 mm. This intense downpour triggered flooding and landslides, impacting several villages and disrupting roads, power supplies and communications in some areas.

Over 3,000 residents were evacuated from Miyun on Sunday, including around 100 residents from Xiwanzi and Gaolingzi villages after their homes were flooded.

Cui Di, deputy chief of Shicheng Township, worked tirelessly through the night to assist with the relocation of residents to safer areas.

"Heavy rain hit on Saturday night, flooding some homes in the town. By Sunday morning, villagers from the most severely affected areas had been evacuated in three batches," Cui said. "During emergencies like this, it's tough for everyone. We do our best to make the shelter as comfortable as possible to ease their anxiety."

Cui noted that local authorities have also prepared essential supplies like mattresses, blankets, bread and eggs for the displaced residents.

Several reservoirs across the city are currently discharging water to manage rising levels, with authorities warning the public to stay away from fast-flowing river sections.