Greece's Transport Minister announced his resignation following a deadly train crash that killed at least 36 people and injured dozens of others on Wednesday.
He said in a statement that resigning was his duty and "the least he could do to honor the victims", adding that he was undertaking the responsibility for the state's "long-standing failures."
Emergency services say at least 36 people were killed in the head-on crash between a freight train and a passenger train near the city of Larissa.
The death toll is likely to rise as more victims are identified. This could take time as DNA analysis will be required, given the level of destruction in the front carriages caused by the crash and subsequent fire, state broadcaster ERT reported.
At least 72 people were taken to hospital, some of them with serious injuries.
There were 342 passengers and 10 railroad employees on the passenger train from Athens to Thessaloniki plus two drivers on the freight train.
Greek Prime Minister Kyriakos Mitsotakis called the accident an "unspeakable tragedy" as he visited the scene at midday. Visibly moved, he promised that the cause of the accident would be fully investigated.
The main task is to treat the wounded and identify the bodies, he said, adding that everything possible would be done to ensure that nothing like this ever happens again.
Transport Minister Kostas Karamanlis promised that no findings would be kept secret.
The Greek government has ordered three days of national mourning for the victims.
Rescue workers were using cranes and other heavy equipment to try and lift the derailed train cars to search for survivors, according to reporters at the crash site near Larissa. Images showed that the front two cars of each train had been destroyed and burnt out.
The passenger train collided head-on with a commercial train traveling on the same track. The passenger train, the Inter City 62, had departed from the Greek capital at 7:22 p.m. (1722 GMT) on Tuesday evening.
Some 350 passengers were said to have been on board.