After excrement was discovered in a Beijing subway train on March 17, parents letting their children defecate in public places has again aroused criticism.

Passengers riding the Beijing Subway Line 13 on March 17 said there was some excrement in a subway train, according to the Beijing News.

Most passengers on the carriage moved to a different one after they saw the excrement.

A passenger surnamed Shan took a picture of the excrement and posted it on Weibo, China’s biggest micro-blogging site. The photo has aroused public anger.

Children have defecated in subway trains before, said a subway employee at the Dongzhimen Station.

He said staff members cannot clean carriages in a timely manner, since the trains only briefly stop at stations.

Beijing subway personnel suggest parents with infants and young children should carry a plastic bag with them while taking the subway.

In November, a photo of a boy squatting in a subway carriage aroused public attention after it was posted on Weibo.

The picture led to a debate on moral standards and complaints about poor access to public toilets.