Updated

Mexico has arrested four members of a radical teachers union in the southern state of Oaxaca, ground zero for the battle over education in the country.

The Federal Prosecutor's Office says in a statement Thursday that police served the arrest warrants overnight.

It says the men are suspected of violently seizing an educational office in Tehuantepec, taking over an oil refinery and distribution center, vandalizing a military base and the theft of 10,000 textbooks.

President Enrique Pena Nieto's government enacted a reform last year designed to wrest control over struggling schools from union officials who exercised wide authority over matters like hiring, firing, salaries and promotions.

The reform has been bitterly opposed by Oaxaca's radical Section 22 union, known for protracted strikes that at times resulted in violence.