Mexico has created a special unit to investigate the disappearance of 43 students last year, yielding to longstanding demands of irate parents who dismiss the government version of what happened.
Prosecutors say municipal police in the southern town of Iguala abducted the students and handed them over to a drug gang, which killed them and incinerated their bodies at a landfill in September last year.
But independent experts have said there was no scientific proof that the students were incinerated at the landfill. They urged prosecutors to seek new lines of investigation.
Parents of the students have long been demanding a new investigation into a case that rocked a country painfully accustomed to drug-related violence.
The Inter-American Commission on Human Rights will oversee the new investigative unit.
Parents of the students had been camping out near the presidential complex since Thursday to demand a new probe.
Attorney General Arely Gomez met them Monday and then announced the makeup of the new investigative team, comprising police, prosecutors and coroners.
A lawyer for the families, Vidulfo Rosales, said that with this step "the investigation takes on a new direction, with new avenues that are going to open up".