Invasion USA?

The Mexican government orders its troops to stay away from the border the day after U.S. lawmen spotted men in military uniforms on this side of the Rio Grande.

Mariano Castillo of the San Antonio Express-News reports that Hudspeth County sheriff's deputies, Department of Public Safety troopers and Border Patrol agents chased three vehicles.

Two of them made it back to the river, where a "a military-style Humvee ... armed with a heavy machine gun" met them on the American side of the border and escorted them across the river. Another vehicle got stuck, and U.S. law enforcement agents photographed men in civilian clothing unloading the SUV.

The Mexican government said it was drug traffickers, not army personnel:

"The government of Mexico denies entirely that this incident involved the Mexican military," said the Foreign Ministry statement, issued Tuesday. "It was done by organized crime, including drug traffickers who are known to use military clothing and equipment."

Homeland Security Secretary Michael Chertoff said last week that reports of Mexican military activity are overblown.