U.S. Customs and Border Protection is investigating a New Year’s Eve incident in which agents used tear gas and pepper spray against migrants attempting to cross the border, the agency said. The incident occurred at the border between Mexico and California as more than 100 people tried to enter the U.S., and some reportedly threw rocks. Children, from toddlers to teenagers, were among those who tried to cross. “To address the rock throwers assaulting agents and risking the safety of migrants attempting to cross who were already on the U.S. side, both smoke and minimal countermeasures were deployed,” CBP said. Pictures from Reuters show the migrants shielding themselves, running and throwing the tear-gas bombs back.