This is the shocking moment a riverside picnic turned into a washout for holidaymakers at a scenic spot.

Visitors set up tents alongside tables and chairs to enjoy the view at the picnic alongside the Luodong River running through the city of Guangzhou in Guangdong, China, on August 17.

But a sudden rise in water levels swept away tents and other possessions from the people who had, until recently, even been swimming in the river with children.

The fast-flowing water that suddenly arrived was also seen carrying debris and even people from further upstream who were caught by the sudden flood waters.

At one point, a woman is seen being washed from downstream, clearly exhausted, and a man wades in to pull her to safety.

Reports say that five people had to be rescued after being caught on a patch of land suddenly surrounded on either side by fast-flowing water.

Eyewitnesses said there was no warning that the flash flood was about to strike, although there had been a slight rainfall earlier in the day. Most of those who turned up decided to go after checking the weather forecast and finding that rain was not predicted.

Onlooker Ms Zhuang, said: 'The river was flowing normally, then suddenly somebody screamed, and brown muddy water replaced the freshwater that had been flowing seconds before.'