Protests have escalated over the disappearance of 43 college students in Guerrero as the government has given conflicting reports about what happened to them.

Investigators said the local police who ambushed the students on Sept. 26 turned them over to a drug gang that apparently had the students killed.

In separate demonstrations on Wednesday, demonstrators shut down the airport for three hours, blocked highways in Chiapas and Chilpancingo, and attacked government and political offices.

Some 500 masked students and teachers broke into the empty Guerrero's state legislature, igniting fires in the library and the chamber where local lawmakers hold sessions, according to Agence France Press.

In a separate incident, protesters torched the education department's audit office in the state capital Chilpancingo.

"The version that students were burned in Cocula, is the third round of supposedly trustworthy confessions made by people who have been detained. We should recall that initially, on October 4, there was the discovering of mass graves in the outskirts of Iguala city. And first the state government prosecutors and then later federal prosecutors said that they had direct participant testimony describing how they had taken the students there, murdered them, dug mass graves and burned them with diesel in these graves," John Gillber, a journalist reporting from Chilpancingo, told Democracy Now!

Gillber added, "It turns out that now the Argentine forensic anthropology specialists have confirmed that 24 of the 30 remains found there have been confirmed not to be the students who are missing. So here we have, you know, now a pattern of the government saying, 'We have these credible witnesses in custody, they've described to us what they did,' but then two weeks later, the scenario they described turns out not to be true. So the statement that they have been murdered and their bodied found in plastic bags in a river outside a trash dump in Cocula, I think should be met with suspicion."

Mexico's President Enrique Pena Nieto is in China this week for the Asian Pacific Economic Cooperation forum. He has used his administration to develop a security strategy to combat years of drug violence and made claims it is having results.

The young men, who are from a teacher college in Ayotzinapa -- one of the few remaining free schools of indigenous and poor people and known for its radical leftwing activism -- had traveled to Iguala to collect funds. However, they also stole four buses to return home when they came under fire. Prosecutors say the city's mayor ordered police to confront the students over fears they would disrupt a speech by his wife.

Parents of the students, who deeply distrust the government, refuse to believe they are dead and say they will only trust DNA results from independent Argentine forensic experts.

The families will head a "National Information Caravan" that will leave from the students' teacher college in Ayotzinapa, near Chilpancingo, on Thursday and head to Mexico's north.

"The goal is to tell people that we continue to demand that the government find them, that for us they are alive and the search must go one," a relative, Epifanio Alvarez, told AFP.

At the request of the families, the government signed an agreement with the Inter-American Commission on Human Rights to assist in the investigation.