Thousands of teachers and students took to the streets in Mexico to demand justice for 43 young men feared to have been massacred by drug-gang hitmen working in cahoots with corrupt police.
Carrying pictures of the trainee teachers who vanished on September 26, the protest in Chilpancingo, capital of the crime-plagued state of Guerrero, was led by some of the anguished parents, who refuse to believe their children are dead.
Some demonstrators wielded sticks, pipes and riot shields stolen from police, but there was no repeat of the violence that has broken out at several other rallies this week.
"This is a social fight, they say we're violent but it's how we have to respond to the murders, kidnappings and collusion with organized crime that goes unpunished," said one teacher, his face hidden by sunglasses and a bandana emblazoned with a skull.
Authorities say the students were abducted in Iguala, in Guerrero state, by police and handed over to a drug cartel before being murdered and set alight -- a claim contested by the victims' families.
"We cannot give up, someone has to answer for these crimes," local activist Osmin Valdez said.
Activists say the students were attacked by police and abducted amid fears they planned to disrupt a speech given by the wife of local mayor Jose Luis Abarca, who was arrested on November 4.
The case has outraged Mexicans accustomed to horrific violence witnessed since former president Felipe Calderon launched a crackdown on drug gangs in 2006.
Protests have rocked a number of Mexican cities this week, with the Guerrero state congress set ablaze on Tuesday in the escalating demonstrations.
Mexico's Senate on Thursday voted to sack the head of the country's National Human Rights Commission, Raul Plascencia, over his handling of the crisis that has rattled the government of President Enrique Pena Nieto.
Plascencia will be replaced by former prosecutor Luis Raul Gonzalez.
Outgoing rights chief Plascencia has also been rebuked for a recent investigation into the military's killing of 22 gang suspects in the central Mexican town of Tlatlaya.
According to NGO Human Rights Watch, Mexico's rights situation is critical.
Some 100,000 people have died or gone missing since Calderon launched the offensive against drug gangs eight years ago.
Separately, religious officials said Friday the remains of a Ugandan priest who traveled to Mexico as a missionary were found in Guerrero, along with another 12 bodies in a clandestine grave.
The corpses were discovered on October 29.
"The remains of Father John Ssenyondo were fully identified," a spokesman for the diocese of the state capital Chilpancingo told AFP on condition of anonymity.
The priest, who was apparently killed by a bullet in the head, was reported missing on April 30.
He was allegedly gunned down for refusing to baptize a child whose parents were not married.
The mass grave was found independently from the search for the missing students.