The two children were left alone in the station hall by their mother, Chongqing Rail Transit said in a statement. "Without a guardian, the two children came near the escalator at the station hall," the statement said.
The incident was first reported by CCTV.
The Chongqing Rail Transport Authority said they were investigating the incident.
"Rail Transit Group is deeply regretful and heartbroken over this case," their statement said. "We also would like to remind all passengers to look after their young children and old folks when traveling, be more alert, and avoid similar accidents."
Both incidents have sparked concerns over the safety of escalators and elevators in China, many of which are failing acceptable standards. Last year there 49 accidents, 21 of which were caused by misuse by passengers, and eight were due to equipment failure, a spokesperson for the Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) of China told the state-owned Xinhua News agency in July.
According to AQSIQ data, almost 5 out of 100 elevators and escalators were found to have problems.
The spokesperson cited poor maintenance as well as aging equipment as safety hazards for several escalators and elevators.
People reacted to the incident on Weibo, with some blaming the mother for leaving the children unsupervised. "Although the parents are the most heartbroken, but this mother will be sentenced if she's in other countries, we don't have any law related to this," one Weibo user commented. Another said that such "circumstances need to be considered" when designing escalators.
Tasneem Nashrulla is a reporter for BuzzFeed News and is based in New York.
Contact Tasneem Nashrulla at firstname.lastname@example.org.
Beimeng Fu is a BuzzFeed News World Reporter covering China and is based in New York.
Contact Beimeng Fu at email@example.com.
Got a confidential tip? Submit it here.