A mystery white foam bursting out of sewage pipes submerged streets in a city in northern China.<br /><br />The video, shot in Xi'an City in Shaanxi Province on Tuesday (May 22), shows a large amount of foam covering a street for more than 200 metres.<br /><br />Workers tried to use water to wash the foam away, but it came out of the manhole again.<br /><br />According to the local Environmental Protection Bureau, the white foam might be caused by leaking washing liquid. Cleaning work to remove the foam has since been finished.
