Mexican officials said on Monday federal riot police occupying the restive city of Oaxaca would remain in place until order was restored, a day after operations to clear out a five-month tent-city protest left one demonstrator dead.
"The goal is to re-establish order," Interior Secretary Carlos Abascal said of the deployment of some 4,000 uniformed police and military to Oaxaca.
Absacal said authorities in no way intended to restrict the rights of the citizenry, but that an armed presence would remain in Oaxaca for an undetermined period of time to restore normality to the southern Mexican city.
He said the federal forces would also ensure the safety of students and teachers as schools which had been shuttered by the protests reopen.
As federal police helicopters buzzed overhead, the streets of Oaxaca were calm on Monday but residents were wary of venturing outside and many shops remained closed. Public transport was suspended.
Mexican police with riot gear, armoured vehicles and helicopters moved in on Sunday to seize back control of the city center, toppling barricades erected by thousands of protesters demanding higher teacher salaries and the resignation of Oaxaca's state governor.
One demonstrator died during the operation and two women were wounded, a spokesman for the protesters said.
The protesters regrouped on the outskirts of the city on Monday and at a university campus, manning barricades and vowing to resist the federal police.
Early on Sunday, protesters set tires and cars alight in streets approaching the central square in an attempt to block police from retaking the city of 60,000, some 450 kilometres (280 miles) from the capital.
The city center had been occupied for weeks by a coalition of leftist groups, who said most demonstrators had tried to avoid clashing with police.
However, some did not heed a call to keep the protests peaceful and confronted police at the barricades, resulting in about 50 arrests, protest leaders said.
Faced with the vast police presence, the demonstrators struck their tent city in the downtown square that came to symbolise the protests.
Mexican President Vicente Fox ordered federal police to Oaxaca on Saturday, one day after a US cameraman for the Indymedia independent news website and two Mexicans were shot dead.
Another 13 people were injured by gunshots in earlier violence, according to reports.
In recent weeks the protests largely paralysed Oaxaca, a popular tourist destination and UNESCO World Heritage Site founded by Spanish conquistadors in the 16th century.
Since May, nine people are believed to have died during clashes between some 70,000 striking teachers and their supporters and the local government.
The teachers have been demanding higher pay, forcing some 1.3 million students to go without schooling.
In June the angry strikers took over government offices demanding the resignation of state Governor Ruiz, a member of the long-ruling Institutional Revolutionary Party (PRI), whom they said had gone too far in putting down demonstrations.
Before the police action on Sunday, the teachers agreed to go back to work this week, paving the way to end the lengthy stand-off between the government and unions.