MEXICO CITY, Mexico - Mexico's president left Sunday on a six-day trip to China and Australia amid angry protests over the suspected massacre of 43 college students by a gang allied with corrupt police.
Angry protesters tried to break into Mexico City's National Palace late Saturday, while others torched several trucks in the southern state of Guerrero, where the students vanished in September.
Thousands of people marched in the capital over a case that has repulsed the nation and triggered the biggest crisis of President Enrique Pena Nieto's administration.
The protests came a day after authorities said suspected Guerreros Unidos gang hitmen confessed to receiving the 43 students from local police, killing them, incinerating their bodies and dumping them in a river in Guerrero.
Authorities said they are still waiting for DNA results to confirm the identities of the remains.
But the apparent mass murder has shattered Pena Nieto's attempts to move Mexico's narrative away from years of drug violence and toward the economic reforms that has earned him international praise.
'Lack of interest'
Despite the unrest, Pena Nieto left for China to attend an Asia-Pacific Economic Cooperation (APEC) summit before a two-day state visit in the country, with which he has sought closer ties.
He will then travel to Brisbane, Australia, for a G20 summit before returning Saturday.
Pena Nieto used a layover in Alaska to defend the trip, telling reporters it would be "irresponsible" for him to miss summits that are important for Mexico.
Amnesty International has criticized his decision to carry on with the trip, saying it "shows the lack of interest in confronting the grave human rights situation in Mexico."
"It's a joke. It shows his lack of moral courage, playing with the feelings and dignity of 43 students," said Juan Gonzalez, a student from the same Ayotzinapa teacher-training college as the missing young men.
Gang-linked police shot at busloads of students in the Guerrero city of Iguala on September 26, in a night of violence that left six people dead.
The police then handed the 43 abducted students to the Guerreros Unidos.
Prosecutors say the city's mayor, worried that the students would interrupt a speech by his wife, had ordered the police to confront them. They are among 74 people, including police and gangsters, detained in the investigation.
The missing students had traveled to Iguala to raise funds but hijacked four buses to return home, a common practice among the young men from a school known as a bastion of left-wing activism.
If the confessions are true, the mass murder would rank among the worst massacres in a drug war that has killed more than 80,000 people and left 22,000 others missing since 2006.
Parents of the students refuse to believe the authorities until they get DNA results from independent Argentine forensic experts, highlighting their deep distrust in the government.
'Pena Nieto out'
In Mexico City, protesters chanted "Pena Nieto out!" and "the people don't want you!"
A small group of 20 protesters used metal barricades as battering rams in a failed attempt to break open the door of the 16th century palace.
They tossed Molotov cocktails at the door, which sparked a brief fire.
Security forces later took back control of the door and detained 14 people, authorities said.
Pena Nieto, who uses the palace for ceremonies and lives in another official residence elsewhere in the mega-city, said it was "unacceptable for someone to use this tragedy to justify violence."
Hours earlier in Guerrero's capital Chilpancingo, more than 300 students threw rocks and firebombs at the regional government headquarters, chanting "they took them alive, we want them back alive."
They also burned around 10 vehicles, including a federal police vehicle.
Mexicans fed up with violence have rallied behind the Twitter trending topic #YaMeCanse, which means "I've had enough."
The words were uttered by Attorney General Jesus Murillo Karam to signal the end of his hour-long press conference on Friday announcing the suspected massacre.