More than 60 members of the militant CNTE teachers union destroyed regional offices of Mexico's governing Institutional Revolutionary Party, or PRI, in the southern state of Oaxaca, a party spokesman told Efe Friday.

"They attacked the offices. They knocked down the main door with a pickup truck, broke windows, furniture, and they cut up the entire telephone system," Rodolfo Romero said from Oaxaca city, the state capital.

The CNTE activists also painted slogans on the walls accusing the PRI of betraying the teachers, whose support was part of the electoral formula that kept the party in power from 1929-2000 and allowed it to retake the presidency in 2012.

The PRI state party filed a criminal complaint with prosecutors and expects authorities to act against the perpetrators, Romero said.

Around 500 members of the CNTE staged a march Thursday in Oaxaca city to protest the education overhaul enacted last year by the PRI administration of President Enrique Peña Nieto.

Romero said that while the bulk of the protesters blocked a street, a smaller group broke away and attacked the PRI offices, which were empty at the time.

The CNTE, representing a third of Mexico's public school teachers, has mounted numerous protests against Peña Nieto's education initiative, which subjects teachers to a comprehensive regime of evaluation.

The union says it does not object in principle to teacher evaluation, only to the "punitive" scheme devised by the government, seen by the CNTE as setting the stage for massive layoffs. EFE