The El Paso-Juárez international bridges are expected to remain open today after the initial U.S. military strikes Sunday against targets in Afghanistan.

“We are still on the same alert status that we went on shortly after the Sept. 11 attacks,” U.S. Customs Service spokesman Roger Maier said. “This means we are conducting continuous enhanced enforcement activities.”

Since Sept. 11, U.S. Customs and immigration officials have checked under the hoods and in the trunks of every passenger vehicle entering El Paso.

“We’ve had calls from the public (Sunday) wondering if the border is open,” Maier said, adding that the average wait at the bridges was 90 minutes, or “a bit longer than usual for a Sunday.”

Antonio Meza, the Mexican consul in El Paso, said Mexico has beefed up immigration reviews of people from “countries with which Mexico does not have many dealings” and has stepped up security at airports.

“Our orders are to detain anyone whose immigration documents are in question and return them to their native countries,” said Jaime Torres, spokesman for the Mexican National Migration Institute.

Laura Benavides of Juárez said she has cut down on trips across the border since U.S. bridge inspections began to take longer. “I go across the border when I absolutely have to,” she said. “I park on the Juárez side, walk across the (Zaragoza) Bridge and catch a ride to wherever I have to go.”

Alma Figueroa, Juárez city civil-protection director, said measures were taken shortly after the September attacks to strengthen security at critical facilities, including Pemex refineries and the Solvay hydrofluoric acid factory.

“The transportation of (hydrofluoric acid) at the border is the riskiest part of the Solvay plant operations,” she said. “The plant produces and transports chemicals every day of the week. We have constant coordination with authorities and emergency planners at all levels, and with the FBI … it’s most likely that the U.S. authorities would be the ones to alert us to any potential problems.”

Trains carry hydrofluoric acid from the Solvay plant in south Juárez through the center of Juárez and to railroad yards in Central El Paso. El Paso emergency officials say the acid is the most dangerous chemical produced in this region. A large accidental or deliberate release into the air could result in mass casualties, making it a potential target for terrorists. Solvay’s corporate offices are in Belgium.

U.S. Customs inspectors check hazardous materials cargo that enters El Paso from Juárez. Maier would not say whether rail cars carrying hydrofluoric acid are getting special scrutiny.

“We are looking at everything more closely,” he said.

At currency exchange houses, where the peso on average was trading at 9.65 pesos to the dollar Sunday afternoon, there were no indications of panic trading, officials said.