Thousands marched in the Mexican beach resort of Acapulco on Friday to demand answers about the fate of 43 missing trainee teachers, who authorities fear were massacred by police in league with gang members.
The students went missing in the southwestern state of Guerrero on Sept. 26 after clashing with police and masked men, with dozens of police being arrested in connection with a case that has sent shockwaves across Mexico.
Authorities say many of the missing students were abducted by police.
Protesters marched in central Acapulco, a resort that in the 1960s was a magnet for Hollywood stars but is now one of Mexico's most dangerous places, because of drug gang turf wars.
"The people are fed up with so much killing," protesters chanted.
While the march passed peacefully, storefronts were boarded up as a precaution and many tourists canceled their plans for a weekend visit. Aside from the marchers, there were few people on the streets. In Acapulco's beach district, however, some tourists continued to relax undisturbed.
Many protesters were calling for the resignation of Angel Aguirre, the governor of Guerrero state, where violence has mushroomed in recent weeks and months.
"Why are they killing us?" 48-year-old laborer Pedro Padilla wanted to know. "We're not here just for the students, but also because of what is happening in many places across Guerrero, where the people are very afraid of the narcos."
Officials have found mass graves in the hills outside the city of Iguala, near the spot where the students disappeared. However, of an initial group of 28 bodies recovered, none of the remains were found to be those of the missing students.
The violence is overshadowing President Enrique Pena Nieto's efforts to focus public attention on sweeping economic reforms aimed at boosting economic growth in Latin America's No. 2 economy.
Pena Nieto took office two years ago pledging to end a wave of violence that has claimed about 100,000 victims since the start of 2007. Although homicides have diminished on his watch, other crimes such as extortion and kidnapping have increased.