Witnesses, Mexican authorities and human rights groups said U.S. Border Patrol agents have begun launching pepper spray and tear gas from San Diego into densely populated Tijuana neighborhoods in response to escalating clashes with smugglers, it was reported Friday.

Border Patrol agents told the Los Angeles Times they have had to counter human traffickers' increasingly aggressive tactics -- especially near Tijuana's most notorious smuggling neighborhood of Colonia Libertad -- by ramping up their own use of force.

Agents have used pepper spray in the past, but usually aimed directly at the smugglers, according to the Times. The new tactics, which saturate large areas, have forced dozens of temporary evacuations and sent some residents to hospitals, witnesses told the newspaper.

Border Patrol officials told the Times that tear gas and pepper spray rarely cause serious injury or damage. Agents say that they use them against assailants trying to divert attention from border crossers by pelting agents with rocks, and that residents are not targeted.

Since Oct. 1, the Border Patrol has counted 90 assaults against agents in the San Diego area, five times as many as during the same period a year ago, and some resulting in serious head injuries, according to the Times.

The acting Mexican consul general in San Diego, Ricardo Pineda, has met with Border Patrol officials to protest the aggressive use of tear gas and pepper spray, Alberto Lozano, the consular spokesman, told the newspaper.

"We told them the Mexican government cannot tolerate having Mexican nationals hit with these kind of devices on Mexican soil by U.S. authorities, regardless of the reason," Lozano told the newspaper.