Mexican authorities denied Thursday that a girl was trapped inside the rubble of a school that collapsed in a powerful earthquake, highlighting the confusion that still reigns two days on.

"We have carried out a full count with the directors of the school and we are sure that all the children are either safe at home, in the hospital or unfortunately died," Angel Enrique Sarmiento, a top officer in the Mexican marines, told journalists at the ruins of the Enrique Rebsamen school in Mexico City.

"There are indications there may be an (adult) still alive in the rubble. There are traces of blood, photographs, as if the person had dragged him or herself and may still be alive," he added.

Rescue workers had told journalists they were certain a girl was alive beneath the rubble, but the different versions of the story varied widely. The story made headlines around the world after the quake, injecting a ray of hope into a tragedy that killed 19 children at the school and more than 200 people nationwide.