U.S. agents shot the gas, according to an Associated Press reporter on the scene. Children were screaming and coughing in the mayhem.
On the U.S. side of the fence, shoppers streamed in and out of an outlet mall.
Central American migrants, mostly men, appear to be trying to breach the border crossing between Tijuana and California.
U.S. Border Patrol helicopters flew low overhead, while U.S. agents held a vigil on foot beyond the wire fence. The Border Patrol office in San Diego said via Twitter that pedestrian crossings have been suspended at the San Ysidro port of entry at both the East and West facilities.
U.S. President Donald Trump took to Twitter again Sunday to express his displeasure with the caravans in Mexico.
“Would be very SMART if Mexico would stop the Caravans long before they get to our Southern Border, or if originating countries would not let them form (it is a way they get certain people out of their country and dump in U.S. No longer),” he wrote.