SAN DIEGO - Border Patrol agents are firing tear gas and powerful pepper-spray weapons across the border into Mexico to repel what the agency said are an increasing number of attacks by assailants hurling rocks, bottles and bricks.
The counteroffensive has drawn complaints that innocent families are being caught in the crossfire.
'A neighbor shouted, 'Stop it! There are children living here,' said Esther Arias Medina, 41, who on Wednesday fled her Tijuana, Mexico, shanty with her 3-week-old grandson after the infant began coughing from smoke that seeped through the walls.
A helmeted agent on the U.S. side said nothing as he stood with a rifle on top of a 10-foot border fence next to the three-room home that Arias shares with six others.
'We don't deserve this,' Arias said. 'The people who live here don't throw rocks. Those are people who come from the outside, but we're paying the price.'
Witnesses in Arias' hardscrabble neighborhood described eight attacks since August that involved tear gas or pepper spray, some that forced residents to evacuate.
The Border Patrol said its agents have been attacked nearly 1,000 times during a one-year period.
The agency's top official in San Diego, Mike Fisher, said agents are taking action because Mexican authorities have been slow to respond. When an attack happens, he said, American authorities often wait hours for them to come, and help usually never arrives.
'We have been taking steps to ensure that our agents are safe,' Fisher said.
Mexico's acting consul general in San Diego, Ricardo Pineda, has insisted that U.S. authorities stop firing onto Mexican soil. He met with Border Patrol officials last month after the agency fired tear gas into Mexico. The agency defended that counterattack, saying agents were being hit with a hail of ball bearings from slingshots in Mexico.
U.S. officials said the violence indicates that smugglers are growing more desperate as stepped-up security makes it harder to sneak across the border. The assailants try to distract agents long enough to let people dash in the United States.
The head of a union representing Border Patrol employees said the violence also results from the decision to put agents right up against the border, a departure from the early 1990s when they waited farther back to make arrests.
'When you get that close to the fence, your agents are sitting ducks,' said T.J. Bonner, president of the National Border Patrol Council.
Border Patrol agents were attacked 987 times along the U.S.-Mexico border during the 12-month period that ended Sept. 30, the agency said. That's up 31 percent from 752 attacks a year earlier, and it's the highest number since the agency began recording attacks in the late 1990s.
About two-thirds of the attacks were with rocks. Many of the rest involved physical assaults, such as illegal immigrants getting into fist fights with guards.
About one of every four attacks occurred in San Diego, and most of those happened along a heavily fortified, 10-mile stretch of the border starting at the Pacific Ocean.
Agent Joseph Ralph estimated he has been struck by rocks 20 times since joining the Border Patrol in 1987, once fracturing a shoulder blade. 'You find yourself trying to take cover,' he said.