The death toll from Tuesday night's train crash in central Greece has increased to 57, authorities said on Thursday.
Forty-eight people remain hospitalized, six of them in intensive care, Greek police spokeswoman Konstantia Dimoglidou told journalists.
A search and rescue operation is expected to conclude on Friday, Greek Fire Service spokesman Vasilios Vathrakogiannis added.
An investigation is simultaneously underway to determine the causes of the crash -- how and why passengers train collided head-on with a freight train traveling in opposite directions.
A station master has been arrested and charged with manslaughter by negligence.
The government has declared a three-day national mourning until Friday and promised that problems affecting the operation of railways will be addressed to prevent such tragedies in the future.
