BEIJING - A blue alert was issued by China's meteorological authority on Saturday with rainstorms expected in the country's northern and southwestern regions in the next three days.

A blue alert is the lowest level in a four-color warning system.

As of Saturday, heavy rain began to hit parts of Sichuan and Guangxi, and will intensify to between 100 millimeter and 180 millimeter downpours on Sunday, the National Meteorological Center (NMC) said in a statement.

Rainstorms will also hit parts of Hebei, Shanxi, Inner Mongolia and Heilongjiang.

On Monday, rain will spread to Chongqing, Guizhou and Yunnan, and most parts of south China.

The NMC warned regions to take precautions against possible disasters due to the rain, including urban waterlogging, floods and landslides.

China has a four-color warning system for strong rain, with red being the most serious, followed by orange, yellow and blue.