The death toll may rise as the passenger train was carrying 352 onboard, said the public broadcaster ERT.

It said the victims include nine railway employees and university students returning to school in the northern port city of Thessaloniki from Larissa and Athens.

Search and rescue teams are working to pull survivors from the wreckage, it noted, adding that at least two cranes are being used to remove passenger carriages.

Many ambulances and fire engines are also at the site and psychologists were sent to the Larissa General Hospital to provide support to the families of the victims and passengers.

Blood donation campaigns were initiated by the Greek Red Cross in many municipalities, including the capital city of Athens.

The 59-year-old station master responsible for overseeing railway traffic in the area has been arrested.

The manager initially denied he made a mistake but later changed his story.

"I made a mistake and sent the passenger train on the same line as the commercial one coming from Katerini (direction)," he said.

Transport and Infrastructure Minister Konstantinos Karamanlis announced his resignation in the aftermath of the deadly collision.

Türkiye offers condolences

Neighboring Türkiye offered condolences, expressing sorrow for the loss of life.

Turkish President Recep Tayyip Erdogan extended condolences to Greece for the fatal crash.

"Stating that he is deeply saddened by the train crash, President Erdogan extended his condolences for those who lost their lives and wished a speedy recovery to the injured," said a statement by Türkiye's Communications Directorate, following a message from the Turkish leader to Greek President Katerina Sakellaropoulou and Prime Minister Kyriakos Mitsotakis

A Turkish Foreign Ministry statement said: “We have learned with sorrow that many people lost their lives and were injured last night as a result of a train crash in our neighbor Greece."

“We extend our condolences to the relatives of those who lost their lives in this tragic accident as well as to the people and government of Greece and wish a speedy recovery to the injured.”

Additionally, in a telephone call, Turkish Foreign Minister Mevlut Cavusoglu conveyed his condolences to his Greek counterpart, Nikos Dendias.