A subway train collided into the back of another train at a station in South Korea’s capital, injuring about 200 people.
About 150 people were treated in hospital for bruises and other mostly minor injuries, officials said, after the incident in Seoul.
A preliminary investigation suggested the moving train’s automatic distance control system might have malfunctioned, officials said.
The driver of the train told officials he applied the emergency brake after seeing a stop signal but was not able to halt in time, Seoul Metro official Jeong Su-young told a briefing.
Fire officer Kim Kyung-su said about 200 people received relatively minor injuries except for two who suffered fractures and serious bruises.
Local media reported there were long delays in providing instructions to passengers about what to do. That struck a nerve in South Korea, where the captain in the April 16 ferry sinking that killed hundreds of people has been condemned for waiting 30 minutes to issue an evacuation order as the ship sank.
The accident comes as South Koreans criticise the government for lax safety practices that many feel contributed to the sinking of the ferry Sewol, which left more than 300 people, mostly high school students, dead or missing.
The subway accident received extensive coverage and was the top news on television and social media sites.