Mexico (search), coming to its powerful northern neighbor's aid for the second time this month, promised to set up shelters for any Americans left homeless by Hurricane Rita.
Nuevo Laredo Mayor Daniel Pena ordered police officers to guide the evacuees, most of them Mexican-Americans who avoided shelters in the United States in the chaotic aftermath of Hurricane Katrina (search).
After Katrina, Mexico sent an army unit to Texas and a navy ship to Louisiana (search) with aid — the first time in more than 150 years that a Mexican military unit was allowed to operate on U.S. soil.
On Friday, temporary permits had been purchased for more than 3,000 cars to cross into Mexico. Most of those who waited in long lines for the permits were legal residents or U.S. citizens, and almost all planned to stay with family or friends in Mexico until Rita passed.
Many drove cars packed with belongings.
"This is like a scene from the 'The Day After Tomorrow,' " David Gallegos said, referring to a film in which Americans pour over the U.S. border to escape devastating climate changes. "It seems half of Houston is heading to Mexico."
Gallegos, a 30-year-old contractor who lives in Houston, drove to the border town of Nuevo Laredo with his wife and year-old daughter and was headed to Guadalajara in central Mexico. They plan to return to Texas next week.
"We have to go back, even if it is to clear the debris," he said.
Some 500,000 Mexicans live in and around the Houston area, according to the Mexican government. Many have family, or second homes, in Mexico.
Those returning said hotels on the U.S. side of the border were filled, forcing many to keep heading south.
Like hundreds of others, Elvia Pratt chose to cross into Mexico to avoid crowded shelters in Texas. A flight attendant from Houston, Pratt said her husband stayed to guard their home.
"We'd rather stay with our family than with 1 million strangers," said Pratt, who was heading to her parents' home in Sabinas Hidalgo, 380 miles from Houston. Her two children, two sisters and seven nieces and nephews were with her.
Nuevo Leon Gov. Natividad Gonzalez promised to set up shelters near the border if needed, and said medical and rescue crews where ready to go to Texas.
"The shelters can be set up in an hour," said Eduardo Gonzalez, a spokesman for the governor.
Some hotels in Monterrey offered discounts to evacuees.