OAXACA, Mexico - As riot police dug in and leftist militants prepared for a final battle, many city residents said Monday they are angry it took the death of an American before President Vicente Fox sent federal forces to end months of political chaos in Oaxaca.

The Fox administration had refused to use force after the activists seized control of the colonial city in June to demand the resignation of Gov. Ulises Ruiz because of alleged repression and corruption. At least eight Mexicans died in that battle and the ensuing unrest.

But then American journalist Bradley Roland Will and three other people were killed on Friday, apparently by city police in civilian clothes who were shooting at the leftists. Within hours, Fox ordered more than 4,600 officers from the Federal Preventive Police to retake the city.

"They let this city rot for six months. Then an American dies, and suddenly they're here," said Armando Ruiz Torres, owner of an Internet café.

The city of 540,000 people remained tense on Monday, one day after police swarmed through barricades and drove militants from the Popular Assembly of the Peoples of Oaxaca, known as APPO, out of their stronghold in the main plaza.

Many militants retreated to the Benito Juarez Autonomous University, where they strung barbed wire and loaded grocery carts with rocks, pipes and Molotov cocktails in preparation for a final stand. A stolen tanker truck carrying cooking gas blocked the entrance of the university, and militants said they would blow it up if attacked.

Other militants harassed the riot police in the center, shooting firework rockets at them, throwing rocks and igniting barricades made out of stolen government vehicles. There were no reports of serious violence, but most downtown businesses remained shuttered.

The toll of dead and wounded from Sunday's raid remained unclear, because the militants took their injured to private homes, fearing they would be arrested at hospitals. But the local Imparcial newspaper published photos of one man killed by gunfire and a teenage boy who apparently died when a rocket exploded in his hands.

The Red Cross and a clinic organized by protesters both told The Arizona Republic they had treated less than 10 people, all for minor injuries.

Rival demonstrations sprung up Monday on opposite sides of the city, one protesting the raid, the other applauding it. But even those who supported Fox's action called it long overdue.

For many residents, the delay was just another act of discrimination against Oaxaca, a poor, mainly Indian state. The city of Oaxaca, 350 miles south of Mexico City, is the state capital.

Will was a reporter for Indymedia, an anti-globalization Web site. Shortly after his death, U.S. Ambassador Tony Garza issued a statement on Friday saying the killing "underscores the critical need for a return to lawfulness and order" in Oaxaca.

But Fox's government has denied the United States pressured it to intervene, or that Will's death was the final straw.