A subway train got a faulty 'go' signal before it plowed into another train in the South Korean capital, slightly injuring more than 240 people, the subway operator said Saturday.

Though the case is still under investigation, the malfunction in the automatic distance control system is presumed to have caused the crash Friday afternoon, Chang Jung-woo, CEO of Seoul Metro, told reporters.

"Normally, the signal should be given in the order of 'stop' and then 'caution.' But at the time of the accident the signal was given in the order of 'stop,' and then 'go-ahead'," Chang said.

The driver of the moving train applied its emergency brakes after noticing the stopped train ahead, but wasn't able to halt it in time, Chang said.

Hospitals treated 249 people, mostly for bruises and minor injuries, though three had surgeries for broken bones, according to Seoul Metro.

Lee Dong-hyun, a passenger on the moving train, described chaos after the crash. "It stopped suddenly ... and everyone screamed," he said. Lee said the door leading to the next car was crushed and couldn't be opened.

The report said the crew of both cars instructed passengers to evacuate and walk to the next station through the tracks. The announcement on the stopped car was made right after the accident, while the moving car told its passengers to wait inside, then announced an evacuation seven minutes after the accident.

People in South Korea are mindful of safety practices, or lack thereof, because the captain of the ferry that sunk April 16, killing hundreds, has been condemned for waiting 30 minutes to issue an evacuation order as the ship sank.


Associated Press writer Hyung-jin Kim contributed to this report.