Classmates of the missing students in Iguala, Mexico -- where a political protest resulting in a series of violent incidents and the disappearance of more than 50 teens -- have vowed radical action if the missing are not returned alive.

Al-Jazeera America reported that the federal government took over the town in Guerrero state Tuesday in order to start searching for the remaining 43 missing students who disappeared Sept. 26 after clashes with the local police. This happened after a mass grave was recently found.

The clashes on that day included a bus full of protesting students from a teachers college. They were shot at by police officers.

The students had been soliciting donations and protesting proposed government education reforms, which critics have said would take away power from teachers unions and increase university fees.

Later that day, masked men shot at two taxis and a bus carrying a soccer team on the highway.

The incident left six dead, and at least 20 suspects, including police officers, had been taken into custody and faced homicide charges.

The presence of the federal officers in Iguala adds to the suspicion that local police conspired with an area drug gang to massacre dozens of students, AJA reported.

Guerrero State Attorney General Iñaky Blanco said that since the arrests of the officers, confessions have confirmed that 17 of the more than 50 students who were first reported missing were handed over to the drug gang Guerreros Unidos.

Guerreros Unidos is a remnant of the Beltran Leyva Organization (BLO), which had once been powerful in the area before arrests of its leaders.

On Sunday the 28 bodies were found in the mass grave, and officials said they could not confirm the identities, but the bodies had been savagely slaughtered.

The students from the teachers college, in nearby Ayotzinapa, have taken control of federal highways and tollbooths in Guerrero in recent days, AJA reported.

"We ask that all human rights organizations, from the local to the international level, help us in demanding justice,"José Solano Ramírez, a student at the Ayotzinapa teachers college, told the Mexican human rights group Serapaz, AJA reported. "They (the students) were taken alive. We want them back alive."