It has residents of Chongqing puzzled and the photographs are rather hard to believe. The Daily Mail reported the Yangtze river, which runs through the city in southwestern China, turned a bright orange red yesterday.

Officials are investigating the cause of the colouring, but residents turned out to marvel at it. One photograph showed one resident collecting a sample of the river’s red content.

One fisherman, however is seen going about his daily business, despite the frightening colour of the river.

It is not the first time a river would turn biblical red in China. The Daily Mail reported that in December, the Jian river in the city of Luoyang, in the north Henan province turned red after it was polluted by a powerful dye, pumped into the city’s storm drain.

Officers then had raided the factories and shut them down.