Students takes part in a protest

Thousands of protesters took to the streets in Mexico on Friday to demand justice for 43 students feared to have been massacred by drug-gang hitmen working in cahoots with corrupt police.
Demonstrators wielding sticks, pipes and riot shields stolen from police marched through Chilpancingo, the capital of Guerrero, the crime-plagued state where the students vanished in September.
"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.
The protesters carried images of the missing male students, who authorities say were abducted 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.
The trainee teachers disappeared on September 26, when police opened fire on buses carrying them in the city of Iguala, killing six people.
Activists say the students were attacked 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.