Despite extensive surveillance, the border remains porous because of the stretches of desert it crosses and Mexico's established smuggling networks. Some Mexican cities, including Tijuana, have sizable Arab populations, giving rise to a recent history of illegal transit of Middle Easterners across the border.
Several incidents in recent months have raised concerns, though none has been confirmed to be terrorist-related.
Earlier this year, U.S. authorities received information that Saudi-born terrorism suspect Adnan G. El Shukrijumah had been sighted in Honduras. Shukrijumah is believed to have been an Al Qaeda surveillance expert who in 2001 helped case the New York Stock Exchange as a possible terrorist target.
After an investigation failed to turn up evidence that he had been in Honduras, U.S. officials enlisted the help of Mexican officials.
"We have no objective evidence to confirm that he is in Mexico, but the alert was sounded, and we are looking for him," Jose Luis Santiago Vasconcelos, chief of Mexico's task force on organized crime, told reporters. "It is difficult to find someone who, it seems, is a ghost."
In August, U.S. authorities issued an alert for a Middle Eastern man who paid what officials said was an unusually large amount of money to be smuggled into the United States near the border town of Tecate, Mexico. He was last seen getting into a waiting black pickup and driving off into the night. Authorities have declined to release further information, or say how they learned how much he paid to be smuggled into the United States.
Last week, the Justice Department announced the arrests of three Michigan residents on charges of running an alien-smuggling operation that brought some 200 citizens of Iraq, Jordan and other Middle Eastern countries to the UUnited States via South America. There is no allegation that terrorism was involved, although a Justice Department spokesman said officials view the case as "a serious border security issue."
And officials are still sorting out the case of Farida Goolam Mahomed Ahmed, a South African woman arrested July 19 by federal agents in the border city of McAllen, Texas, after swimming across the Rio Grande.
Ahmed had traveled from Johannesburg, South Africa, via Dubai, United Arab Emirates, to London and then to Mexico City about July 14. Authorities said her passport had pages missing and she had an airline ticket to New York. A member of Congress was quoted as saying that she was on a terrorist watch list but officials declined to confirm that information. Farida, 48, remains in custody on charges of violating immigration laws.
