The train's guard, Koksal Coskun, and its two drivers, Fikret Karabulut and Recep Sonmez, have been charged with causing the death of several people through negligence and carelessness and are being held in custody, the NTV news channel reported on Saturday.
The newly introduced fast express train, with nearly 250 people aboard, derailed on Thursday near the northwestern town of Pamukova while on its way from Istanbul to the capital Ankara, its five carriages overturning and crashing into each other.
The crisis centre at the prime minister's office on Saturday increased the death toll from the tragedy from 36 to 37 after authorities identified a new victim.
Eighty-one people were injured in the accident.
Turkish officials have said they need to carry out a full technical investigation before they can give the cause of the accident, but Transport Minister Binali Yildirm told a press conference on Friday the drivers had exceeded the speed limit.
Yildirim said the train was travelling at 118km an hour, whereas the speed limit in the area of the crash was 80km an hour, but he refrained from directly putting the blame on the drivers.
"Authorities have accused the train's staff after saying they never required the train to move at high speeds, but in fact, it was impossible to reduce the duration of the trip without breaking all the rules"
head of the Hur Anadolu transport trade union
But in remarks which contradict the minister, the lawyer for the three charged men, Ismail Gurses, told the Anatolia news agency his clients were told by railway authorities the train should move along at a speed of 130km an hour at the accident site.
Several Turkish newspapers on Saturday published a page of an official booklet distributed to engine drivers which corroborated Gurses' claim.
According to the booklet, drivers could move at 130km an hour at 200m before the accident site, but they were supposed to have reduced the speed to 80km an hour 100m away from the site, the liberal Radikal daily said.
"The document of lies," said the mass-circulation Hurriyet daily on its front page, while the popular daily Vatan wrote: "Evidence of murder".
The cause of the crash is yet to
Trade unions and civic groups announced they would file complaints against Prime Minister Recep Tayyip Erdogan, Yildirim and the head of the railway authority over the accident, accusing officials of turning the train's guard and drivers into scapegoats.
Breaking the rules
"Authorities have accused the train's staff after saying they never required the train to move at high speeds, but in fact, it was impossible to reduce the duration of the trip without breaking all the rules," Yavuz Zegerek, the head of the Hur Anadolu transport trade union, said.
The new train linking Istanbul and Ankara opened last month with much fanfare despite warnings the country's decrepit tracks, untouched since the 1950s, would not withstand high-speed cars.
The so-called "accelerated" train travels at speeds of up to 150km an hour, reducing the duration of the 567km trip from Istanbul to Ankara from eight to five hours.
Turkish authorities have denied accusations safety measures were neglected when the new train was launched, and Erdogan on Friday rejected calls for heads to roll over the tragedy.