Thousands of people have marched in the Mexican city of Oaxaca in the latest protests against the state governor and the security forces.
The protesters are demanding the resignation of Gov Ulises Ruiz
Thousands of armed riot police faced the protesters, who are calling for the removal of Governor Ulises Ruiz.
Several people have died since the crisis began some five months ago.
The protesters took shelter on a university campus last month after riot police - sent by President Vicente Fox - evicted them from the city centre.
Gov Ruiz has refused to step down despite accusations of corruption, authoritarianism and electoral fraud.
The protests were initially led by teachers striking for better working conditions, but their ranks have been swelled by leftist activists.
Last week saw fierce clashes between the protesters and the police, which left eight people hurt.
Police used water cannon and teargas as crowds threw petrol bombs.
Crowds at Sunday's protest shouted slogans against the security forces, demanding they withdraw.
Esther Guzman, a teacher quoted by the Reuters news agency, said people were willing to die to achieve their aim.
"The people are demanding the Oaxaca governor goes, even though there is blood," he said.
The protests began in May, when teachers went on strike for better pay but escalated in June when police moved in to disperse protesters from the city centre.
Thousands of schools have been closed since the strike began, leaving 1.3 million children unable to attend classes.