Earlier on Sunday the interim governor of Guerrero, Rogelio Ortega, announced three days of mourning after the remains of one of the 43 students who disappeared in the Mexican state were identified.
Also on Sunday, the Mexican authorities announced that they have enough evidence proving that students were incinerated at a garbage dump by members of a drug gang.
Authorities have said the remains were then placed inside plastic bags and thrown into a river, according to a CNN report.
But the parents of the missing are demanding that the search must continue.
"If these murderers think that with a DNA match of one of our boys, we are going to stop and cry, we want to tell them that they have been mistaken, that after today, this day of action will continue until we find the remaining 42 alive," CNN quotes Felipe de la Cruz, a spokesman for the students' families as saying.
"My son, wherever you are, I'll keep looking for you, even if my heart is breaking from the news," the news channel’s website quotes one father as saying,
At a news conference Sunday, Mexican Attorney General Jesús Murillo Karam vowed to continue with the investigation until they detain all the culprits.