Television footage showed the three-storey building in flames, with fire engine teams trying to put out the blaze.
Demirtas said some terrified schoolgirls were injured after jumping out of the window to escape the flames. He added that none of the injuries were serious condition.
The governor said the fire at the private schoolchildren dorm broke out at around 19:25 (1625 GMT) and it was brought under control some three hours later.
Demirtas declined to comment on claims that fire escape stairs were locked and students were unable to use them.
But Adana city Mayor Huseyin Sozlu said: “It appears that the fire escape stairs door was locked. Children could not open it. Bodies were found there,” he said.
He told NTV “of course children would have survived” if they had been able to flee down the fire escape stairs.
“From tomorrow the governor’s office will start an investigation.”
He said the children were aged between 11-14.
