Shanghai police said they are investigating an incident in which six bus passengers urinated on one of the city's elevated roads, local media reported on Monday.

A picture showing the six men urinating on a low barrier on an elevated road was posted on Sina Weibo, a Chinese micro blogging website, and immediately stirred online indignation, the Xinmin Evening News reported.

Local police found the bus and said that it had stopped near the city's Gonghexinlu junction on the north-south elevated road .

The bus driver said the men were from Denmark and had been drinking all the way and grabbed the steering wheel to force him to stop on the elevated road, according to the report.

Shanghai police did not make it clear what kind of measures they will take after finding the offenders. But there have been previous examples in other parts of China in which people who urinated in the street were held under administrative detention for seven days for “deliberately showing their body” in public places. According to China's Law on Public Security Administration passed in 2005, people who behave in such a way and cause a severe negative social impact could be detained for five to 10 days.

Foreigners in China who don't have diplomatic immunity are subject to same punishment.