MEXICO CITY - Protesters marched in Mexico City on Thursday to demand authorities find 43 missing college students, trying to step up pressure on the government on a day traditionally reserved for the celebration of the 1910-17 Revolution.
About 200 youthful protesters, some with their faces covered in masks or bandannas, scuffled with police as they tried to block a main expressway to the capital's international airport. Protesters hurled rocks, fireworks and gasoline bombs at the police, at least one of whom was hit by the projectiles.
Some passengers had to walk to the terminal, but flights were not interrupted and the expressways were reopened.
Authorities decided to cancel the traditional Nov. 20 Revolution Day march, but did not give a reason.
Bus caravans carrying the relatives and family members of the 43 missing college students converged on the capital after several days crisscrossing the country.
The caravans were expected to head three march routes converging on Mexico City's main square.
Nowhere are the protests more impassioned than at the school the students attended. Uriel Solis, is one of 14 who got away from a group of police.
The students were on a bus going to Iguala to raise money for a human rights March. Federal officials say Iguala's mayor feared the group would disrupt an event for his wife and had police stop them. The officers opened fire.
Solis played dead, but he knew he had to escape when another group of men arrived.
"They were dressed all in black," Solis told CBS News. "Wearing hoods and carrying large guns. They started shooting, too.
"We ran and hid for six hours," he said. "At first we were afraid to speak out. But now, even though I'm alive, I feel dead. I don't fear death anymore."
The students from a rural teachers college disappeared on Sept. 26, when they went to the city of Iguala in southern Guerrero state to hijack buses.
Iguala police intercepted them on the mayor's orders and turned them over to the criminal group Guerreros Unidos, a gang with ties to the mayor, prosecutors say.
Prosecutors say there is evidence the gang members killed the students and incinerated their remains, but the families have rejected that account and the marches were intended to keep pressure on the government to find them.
Prosecutors have sent badly burned bit of bone and teeth found at a garbage dump in Guerrero to a laboratory in Austria to see if any DNA samples can be recovered to help identify the remains.