At least 14 hikers were killed when a flash flood swept them away in a canyon in southwest China, as torrential rain battered the area, state media reported Sunday.

Five people were still missing after a tour group hiked into a forbidden part of a canyon in Chongqing Saturday using a local resident as a guide, the official Xinhua news agency reported.

The remaining 16 of the group -- all Chinese nationals -- were rescued after a downpour triggered the mountain torrent that swept some of them away.

"I heard a roaring sound while walking at the bottom of the gorge, and suddenly the flood, up to several metres high, crushed upon us and swept us several kilometres away," Deng Ke, one of the survivors, was quoted as saying.

"I grabbed a rattan and climbed about 30 metres (100 feet) along the mountain until I met some villagers," he said.

Nearly 2,000 police officers, soldiers, medical staff and local residents were searching for the five missing tourists, Xinhua said.

The incident came as torrential rains had battered the area for three days, forcing the evacuation of nearly 4,000 people, and triggering landslides that left another two people dead and four missing.

The rain, which was forecast to calm down from Sunday to Monday, flooded 9,000 hectares (22,200 acres) of crops.

In neighbouring Sichuan province, two people went missing and more than 100,000 others were displaced due to heavy rain, Xinhua said.

South and central China are prone to major flooding during the annual summer rainy season that every year causes heavy casualties.