GUANGZHOU - Torrential rains on Saturday lashed multiple cities in south China's Guangdong province including Zhongshan and Zhuhai, with 58 rainstorm alerts in effect across the province.

From 8 am to 5 pm Saturday, seven townships and sub-districts in Guangdong recorded precipitation of over 250 mm, and 65 townships and sub-districts recorded 100 mm to 250 mm, according to the Guangdong meteorological observatory.

A township in the city of Zhongshan recorded the highest precipitation of 385.9 mm.

Since April, Guangdong has been hit by sustained heavy rains rarely seen in history, leaving some water conservancy projects damaged and water levels in 113 reservoirs still above the warning level, said the provincial water resources department

Of the 58 rainstorm alerts in effect by around 3 pm Saturday, five were red alerts and 14 were orange alerts, according to the provincial meteorological authorities.

ALSO READ: China renews yellow alert for rainstorms

China has a four-tier, color-coded weather warning system, with red representing the most severe warning, followed by orange, yellow, and blue.

The meteorological authorities in Zhongshan issued a red alert for rainstorms covering the whole city at 4:05 pm Saturday, with the precipitation in two areas within three hours reaching 100 mm. Local authorities have ordered the temporary closure of parks.

The rains have led to the temporary suspension of some bus services and the closure of some scenic spots in Zhuhai. One meteorological station recorded precipitation of 315.8 mm in six hours to noon. Another meteorological station recorded precipitation of 141 mm within one hour, the largest one-hour rainfall since records began in 1962.

On Saturday afternoon, police authorities in Zhuhai closed part of an expressway as there is a risk of a landslide.

ALSO READ: Death toll rises to 48 after road collapse in China's Guangdong

In Guangzhou, the provincial capital, 46 departure passenger flights had been delayed by more than one hour and had not taken off by 6:09 pm Saturday, according to the Guangzhou Baiyun International Airport.

The provincial meteorological authorities ordered precautions against flash floods and geological disasters as further rainstorms are expected in the coming days.

The provincial transport department has ordered a sweeping check-up for potential geological risks for the roads, waterways and railways.

Since April, Guangdong has been hit by sustained heavy rains rarely seen in history, leaving some water conservancy projects damaged and water levels in 113 reservoirs still above the warning level, said the provincial water resources department. It has ordered check-ups of the water conservancy projects for potential safety risks.

Meanwhile, the province has set up a disaster investigation and assessment team headed by the provincial governor for a deadly expressway collapse.

READ MORE: 24 dead after expressway collapse in China's Guangdong

The cause of the disaster is under investigation and assessment, according to local authorities.

As of 2 pm on Thursday, the death toll has risen to 48 after part of the Meizhou-Dabu Expressway in Meizhou city collapsed around 2:10 am Wednesday. The DNA of another three people has yet to be identified. Thirty others were injured, and none are in life-threatening condition.