No signs of Qaeda at U.S.-Mexican border: official

The metal border fence stretches across a valley separating the US and Mexico, near Campo, California on March 17, 2008.

WASHINGTON (Reuters) - Authorities have seen no signs of al Qaeda trying to insert operatives into the United States from Mexico, but the militant group has considered doing so, a U.S. intelligence official said on Friday.

The comments by Charles Allen, Homeland Security undersecretary for intelligence and analysis, could undercut one argument by advocates in and out of government for get-tough tactics to fight illegal crossings at the southern U.S. border -- that they are needed to fight terrorism.

In contrast, at least one Islamist militant has been caught trying to enter the United States from Canada by land to attempt an attack.

"We know of no trained al Qaeda operatives who have crossed over our southern border," Allen told reporters.

"We do know that going back to 2004, the southern border is something that al Qaeda's central leadership has looked at. But we know of no specifics of where al Qaeda has really endeavored to cross our borders in the south," he said.

The U.S. government is seeking to complete this year a planned 670-mile border fence to fight illegal crossings from Mexico.

Homeland Security Secretary Michael Chertoff has cited the anti-terrorism argument in waiving environmental laws and other legal restrictions to quickly build the fence.

"The flow of illegal traffic through the border region imperils our ability to fight terrorism by stopping the illegal entry of terrorists," the Homeland Security department said earlier this month in justifying the latest waivers, for 500 miles of potential fencing.

Allen said there have been militant "sympathizers and fund-raisers for Hizbollah" trying to cross from the south, but no trained operatives have been discovered.

SUFFICIENT THREATS

A Homeland Security Department official said those crossings, and the potential for operatives to cross, are sufficient threats to help justify the fence construction's urgency.

On the other hand, Vancouver-based militant Ahmeed Ressam, with suspected links to al Qaeda, was stopped with explosives in his car at the U.S. border with Canada in December 1999, foiling a suspected plot to bomb Los Angeles.

The United States was working closely with Canadian authorities, Allen said, and he credited them with breaking up in 2006 a plot by militants to carry out an "al Qaeda-inspired" bombing campaign in the Toronto area.

Allen also said al Qaeda is trying to recruit both white and nonwhite people so it can train "western-looking" operatives to help it carry out attacks in Europe and the United States.

No such suspects have yet been caught trying to enter the United States, but the effort remains a concern. "This is something to which we must pay a lot of attention," Allen said.

He said al Qaeda shifted its strategy to seek Western-appearing recruits after the December 2005 death of al Qaeda external operations chief Abu Hamza Rabia. Rabia recruited operatives who had little experience with the West, he said.

(Editing by Sandra Maler and Bill Trott)