CHENGDU - Four people were missing and three bridges had collapsed in southwest China's Sichuan province as of Tuesday afternoon after severe rainstorms battered the region, including some quake-stricken areas, local authorities said on Tuesday.

A bridge collapses due to rainstorms in Deyang city, Southwest China's Sichuan province, July 9. [Photo/Xinhua]

The province has seen rainstorms since Monday evening. Rain-triggered flooding has left four people from the quake-hit counties of Beichuan, Anxian, and Qingchuan missing, according to the provincial flood control and drought relief headquarters.

Three bridges have collapsed since Monday evening due to rain-triggered floods in the cities of Jiangyou and Deyang, the headquarters said.

Three major rivers in the province have been swollen, with water levels surpassing warning marks, it added.

Heavy rain started to batter the city of Ya'an, which was shaken by a 7.0-magnitude earthquake in April, early on Monday morning, resulting in floods in three townships in the city's Yucheng District, according to the district government.

At least 16,900 people in 4,920 households in the district have been affected. Direct economic losses are estimated at 768 million yuan (125.18 million U.S. dollars).

Local governments have relocated over 5,200 residents and tourists to get them out of the way of potential geological disasters.

Downpours also submerged quake-razed ruins in Beichuan Qiang Autonomous County, which has received 300 mm of precipitation. More than 42,000 people in Beichuan have been affected by the downpours.

An 8.0-magnitude earthquake hit Beichuan in May 2008, leaving 20,000 people dead or missing.

Communication and traffic in many townships of the quake-hit counties of Wenchuan, Beichuan, and Lushan were cut off on Tuesday.

Floods also caused a landslide in the village of Shilibei, as well as cutting telecommunications and access to roads in many townships in Beichuan.

The Beichuan county government has relocated 2,019 residents as a precaution.

At Shuangliu International Airport in the provincial capital of Chengdu, 4,000 passengers have been stranded, as more than 23 inbound and outbound flights have been affected by the weather.

The storm has also caused trains running on the Baoji-Chengdu Railway to be delayed or rerouted.

The Sichuan Provincial Meteorological Center has upgraded its orange rainstorm alert to red, with torrential rain and thunder expected in Chengdu, Ya'an and Deyang.

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

In neighboring Gansu Province, over 100,000 people from 14 counties and districts have been affected by rain-triggered floods.

Three villagers remain missing after falling into raging floodwater on Monday evening. Search and rescue efforts are under way.

Authorities in the city of Longnan issued a yellow alert for heavy rain early on Tuesday, as the rain has been pounding the city since early Monday.

Local authorities also warned of the risk of potential geological disasters.