(CNN) — US Customs and Border Protection says it is investigating an incident at the California border with Mexico, in which agents used tear gas, pepper spray and smoke as more than 100 migrants tried to enter the country illegally.
Some of the migrants threw rocks as others lifted children over the razor-edged wire late Monday in the San Diego sector, the agency said a statement, which was based on initial reports. The confrontation continued into the early hours of Tuesday morning.
One image distributed by Reuters shows a man covering his mouth as he is surrounded by smoke. Another shows people going over the wall as armed agents stand on the US side.
About 150 migrants approached the fence, but about one-third of the group members turned back into Mexico when they saw Border Patrol agents, CBP estimated.
Others tried to enter the United States by going over or under the fence. The agency said teenagers wrapped in jackets, blankets or mats were put over the wire, as were “toddler-sized children.”
“Once again we have had a violent mob of migrants attempt to enter the United States illegally by attacking our agents with projectiles,” said Katie Waldman, a spokeswoman for the Department of Homeland Security. “As has happened before — in this and previous administrations — our personnel used the minimum force necessary to defend themselves, defend our border, and restore order.”
CNN has reached out to Families Belong Together, an advocacy group that works with migrants at the border, but didn’t get an immediate response.
Waldman said there were no reported injuries among the people throwing rocks. She called on Congress to act on funding for a border wall, amend the Trafficking Victims Protection Reauthorization Act, and end the Flores settlement agreement.
Twenty-five people were apprehended, CBP said, without elaborating about where the detainees were sent. The agency said an internal investigation is underway.
The incident comes a little more than a month after a similar incident in which agents fired tear gas at migrants, igniting anger, debate and concern. The group included mothers and children, and a photo of Maria Lila Meza Castro and her kids captured national attention. They were later allowed into the country to await asylum hearings.