|Attack against Guerrero state congress in Chilpancingo|
Protesters accuse local politicians of failing to investigate the students' disappearance
Five vehicles were set alight outside the building in the state capital, Chilpancingo.
The students disappeared in the nearby town of Iguala more than six weeks ago.
Mexican officials say local gang members have confessed to killing the students and burning their bodies.
But remains found nearby have not yet been identified as the missing students.
The students' disappearance has led to weeks of violent protests across the country.
|There were violent clashes in several areas of Chilpancingo during the day|
It came after protesters torched the education department's audit office in Chilpancingo during a demonstration called by the teachers' union.
On Tuesday demonstrators in Iguala attacked the regional headquarters of the ruling party (PRI).
|Guerrero's Education Department building was also targeted during teachers' union march|
Investigators said that municipal police officers confessed to seizing the students, who had been protesting in Iguala on 26 September, and later handing them over to the gang.
Iguala Mayor Jose Luis Abarca is under arrest on suspicion of ordering police to intercept the students. Iguala's police chief is still on the run.
But residents say they suspect links between the gang and officials reach higher levels than that of the local town council.
|Jose Luis Abarca and his wife, Maria de los Angeles Pineda, 7 Nov 14|
The couple were arrested last week in Mexico City hiding in a slum area
Tests carried out by the Guerrero state authorities suggested the bodies they contained were not those of the students.
But Mexico's Attorney-General Jesus Murillo Karam later said the initial tests may have been flawed.
|Attorney-General Jesus Murillo Karam|
The charred remains have now been sent to a specialised laboratory in Innsbruck, Austria, for testing. Results are not expected for several weeks.