A stampede on a malfunctioning escalator at a subway station in Shenzhen, Guangdong Province, left 25 people injured Tuesday morning and led to complaints over subway staff's slow response to the incident.

Dazed commuters sit on the ground of Guomao Station at Shenzhen's subway line No.1 Tuesday morning after a stampede triggered by a malfunctioning escalator left 25 people injured.

An upward-moving escalator at Guomao Station on subway line No.1 loaded with passengers suddenly began to move downward at about 8:50 am, causing several passengers to fall and triggering a stampede, China Central Television reported.

The injured passengers were sent to local hospitals for treatment after the accident. The cause of the malfunction remained unclear, a spokesman surnamed Tang from the Shenzhen Metro Group said at a press briefing at about 11:30 am Tuesday.

Most of those affected received injuries to their legs and feet, and many suffered deep bruising. One passenger broke his leg, according to a report on sznews.com.

A pregnant woman surnamed Gong was among the injured. She suffered bruising in two of her fingers and swollen knees.

A report from the local Luohu Hospital said that her baby remained safe.

An Internet user who identified herself as a witness to the accident uploaded photos on her microblog on sina.com at 10:50 am Tuesday, saying that she suffered a twisted foot, and claiming that some of the injured were bleeding.

"There was a bunch of injured people waiting there for help, and I was the only one who managed to make my way out," she said in her post.

A passenger surnamed Ma said that he heard a loud noise from the escalator before it started moving downward, the report said.

Another passenger surnamed Huang, who injured his legs in the accident, complained that the subway company did not provide first aid quickly enough. The injured passengers were only taken to the lobby of the subway station by workers 20 minutes after the accident, and were sent to the hospital 30 minutes later, Huang said.

Calls made by the Global Times to the Shenzhen Metro Group went unanswered Tuesday.