A mob attacked four Mexican police officers in Santiago Atlatonga, near the ancient pyramids of Teotihuacan, on Wednesday, then took three other officers hostage, authorities said.

　　Trouble began when four Mexico state police officers tried to take four people into custody, one of them a local justice of the peace. A group of residents claiming authorities did not have arrest warrants retaliated by hurling stones and trash.

　　Responding to an emergency call from their colleagues, over 150 state police officers flooded the area and rescued the four officers, some of whom sustained minor injuries, said a spokesman for the government of Santiago Atlatongo, located just north of Mexico City in Mexico state, which forms a crescent around much of the capital.

　　Police helicopters soon encircled the town, and an additional 250 state police officers in riot gear arrived. They fired tear gas to disperse the mob, but residents set up barricades of burning tires and blocked highways leading into the area.

　　Locals eventually took another group of three Mexico state police officers hostage and locked them inside a school, demanding the immediate release of people arrested during clashes with police.

　　In a statement, Mexico state said the original group of police officers headed here as part of a larger sting operation against illegal dumping.

　　Authorities said the three police officers were not hostages, but had simply holed up in the school to negotiate with town leaders. But a large group of people could be seen standing watch outside the school, ensuring the trio did not leave late on Wednesday night.

　　Authorities across Mexico remain on alert for cases of vigilante justice after a mob killed two federal agents in a community on Mexico City's southeastern outskirts in November.

　　Three plainclothes officers were photographing a school as part of an anti-drug operation when they were attacked by hundreds of residents who believed they were kidnappers.

　　The three were savagely beaten. Two of them were doused with paint thinner and set ablaze, and their deaths were captured on tape and repeatedly televised nationwide.

　　About three hours passed between the time local news media reported problems and the agents' deaths. Both federal and city officials failed to get forces to the site.