MEXICO CITY - Mexican President Enrique Pena Nieto marked two years in office Monday with his lowest approval rating yet, as thousands protested again his handling of the presumed massacre of 43 students.
A poll published by El Universal newspaper showed just 41 per cent of Mexicans approve of his performance, while the daily Reforma found 39 per cent were satisfied.
It was the worst approval rating for a president since Ernesto Zedillo in the mid-1990s, underscoring the magnitude of the crisis Pena Nieto is facing since the 43 students vanished in September.
In the latest protest to hit the country, thousands of people marched in Mexico City, chanting for Pena Nieto to resign and waving blackened flags in anger over the case of the missing students.
"I put myself in the place of the mothers who don't know where their children are, and it's hard, it's painful," said Reina Cruz, 66, as others shouted "Pena out!" Thousands more protested in the southern state of Guerrero, where a drug gang has confessed to killing the aspiring teachers after local police handed them over in September.
A group of protesters ransacked the Guerrero state prosecutor's office in the regional capital, Chilpancingo, and set five vehicles on fire, including two police cruisers.
"We no longer recognise Enrique Pena Nieto as president of Mexico, because he has not met our central demand, which is to present our sons alive," said Felipe de la Cruz, a spokesman for the families of the missing.
Families refuse to believe the 43 young men are dead and demand they be found alive. Federal prosecutors have stopped short of declaring them dead, saying they await DNA tests on charred remains sent to an Austrian university.
Teachers and students led another protest in the neighbouring state of Oaxaca, where some 1,500 people blocked the local airport for four hours, causing two flight cancellations.
Pena Nieto, meanwhile, announced that he had sent constitutional reforms to Congress aimed at disbanding the country's notoriously corrupt municipal police forces to allow the federal government to take over gang-infiltrated towns.
The president unveiled the plan last week, two months after the students were attacked by police in the city of Iguala, allegedly under the mayor's orders.
The case has put a spotlight on Mexico's struggle to end corruption and impunity amid a drug war that has left 100,000 people dead or missing since 2006.
"What happened in Iguala marks a before and an after," Pena Nieto said Monday during a visit to the impoverished southern state of Chiapas.
"It showed the institutional weakness to face organised crime, which today have more numbers, weapons and power than in the past," he said.