Pena Nieto said he "instructed the investigations into the tragic events in Iguala to take into account the elements provided by the (independent experts)."

The president also offered to meet again with the parents of the victims. Though he gave no date, the parents have demanded a meeting before Sept. 10, the daily Milenio reported.

The five-member group of experts ruled out the possibility the students were incinerated in the way and in the place the PGR had affirmed. Their report also indicated state and federal authorities had knowledge of the events as they unfolded, contradicting the initial conclusion that only corrupt local police in Iguala cooperated with the criminals.

All 43 students were enrolled at a rural teachers college, the Raul Isidro Burgos in the town of Ayotzinapa, which is known for its leftist activism.

According to the survivors, some 100 students set out aboard two buses on the afternoon of Sept. 26 towards the state capital Chilpancingo, where they planned to raise money for a longer trip to the nation's capital, Mexico City, to take part in an Oct. 2 march commemorating the "Tlatelolco Massacre," an attack on university students in 1968.

Soon after, in a clash with local police trying to stop the buses from advancing, six people were killed, 25 were injured and the 43 went missing.