"The mountainous base is 1,100 to 1,200 meters above sea level and the rainstorm has had a minimal impact on it," said Zhang Guiquan, a panda expert at the base.

"Before the flood season, the base initiated an emergency response system against possible rainstorms. When the rainstorm hit Ya'an, keepers recalled all pandas playing outside the dens," he said.

Wolong has some 170 captive pandas and more than 80 are in its Bifengxia base in Ya'an.

More than 200 flights at Shuangliu International Airport in Chengdu were cancelled because of the severe weather, said Lu Junming, an airport information officer.

"Some of the inbound flights had to land in airports in Mianyang and Nanchong in Sichuan, Xi'an in Shaanxi province, Guiyang in Guizhou province and Lanzhou in Gansu province," he said.

In Chengdu, food prices rose because of the rainstorms.

At produce market near Shuhan Road, a kilogram of tomatoes sold for 9 yuan, four yuan more than normal, and blanched garlic went for 18 yuan, a 2 yuan hike.

"Fewer farmers have sent vegetables to the city because of the rainstorm," said vendor Xia Bi.

The Sichuan Provincial Meteorological Center has upgraded its orange rainstorm alert to red, as more rain is expected in Dujiangyan, Beichuan, Ya'an and Wenchuan over the next three days.

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, three villagers remain missing after falling into floodwaters on Monday evening. Search and rescue efforts are underway, according to Xinhua News Agency.

Authorities in Gansu's Longnan issued a yellow alert for heavy rain early on Tuesday, as storms have been pounding the city since early on Monday. Local authorities also warned of the risk of potential geological disasters, Xinhua said.