"There are signs of these kinds of problems present today, and [they are] progressing," Fox told reporters this weekend. "We have to act quickly and on time to prevent these kinds of actions."

The paper said Mexico's National Human Rights Commission believes a number of such grass-roots organizations are being formed, especially in the wake of the passage of Proposition 200 in Arizona – a voter-approved measure requiring proof of citizenship to vote and receive some public benefits.

"We totally reject the idea of these migrant-hunting groups," Fox said. "We will use the law, international law and even U.S. law to make sure that these types of groups, which are a minority ... will not have any opportunity to progress."

Backers of such groups say what they are doing is well within U.S. law. And group organizers say they aren't looking to intercept illegals themselves, but instead will notify Border Patrol agents when illegal migrants are spotted so Border Patrol agents can make the arrests.

"Vicente Fox can rant and rave all he wants, but he obviously doesn't understand what a democracy means," Chris Simcox, a co-organizer of the Minuteman Project, told the Republic. "We have been working within the law."

Fox, who will be in Texas next week to meet with President Bush and Canadian Prime Minister Paul Martin, also criticized recent U.S. legislative efforts to fund construction of border fences.

"We are convinced that walls don't work. They should be torn down," he told reporters. "No country that is proud of itself should build walls. No one can isolate himself these days."

A number of U.S. lawmakers say they are concerned about possible infiltration of terrorist elements into the U.S. via Mexico, after American intelligence officials testified recently that there is evidence al-Qaida and other groups may try to infiltrate from south of the border – like hundreds of thousands of Mexican migrants every year.

Fox, however, downplayed those concerns. Regarding terrorists using Mexico as a transit point into the U.S., he said, "We have absolutely no evidence of that."

Editor's note: