Officials said all the migrants were being moved to a former concert venue much farther from the border. The city said in a statement the sports complex shelter was closed because of "bad sanitary conditions."

Experts had expressed concerns about unsanitary conditions that had developed at the partly flooded sports complex, where the migrants had been packed into a space adequate for half their numbers. Mud, lice infestations and respiratory infections were rampant.

The remaining migrants were taken by bus to the new shelter about 10 miles from the border crossing at Otay Mesa and 14 miles from San Ysidro, near where people line up to file applications for asylum in the United States.

Tijuana officials had said earlier that nobody would be forced to move to the new facility, a large building and concrete patio known as El Barretal that was used for concerts and other events until about six years ago.