RNA - US Customs and Border Protection stated that the measures were used to address a group of migrants who were reportedly throwing rocks at agents, The Hill reported.
"Agents deployed smoke, pepper spray and CS gas to a position upwind of the rock throwers and south of the border fence," CBP said in a statement Tuesday, adding that the deployments were not directed against the migrants.
An Associated Press photographer reported seeing at least three rounds of gas launched on Mexico's side of the border near Tijuana.
The AP reported only seeing rocks thrown after the tear gas was fired, noting that it affected the group migrants, which included women, children and journalists.
Department of Homeland Security (DHS) Spokesperson Katie Waldman told The Hill in a statement that the migrant group was to blame for putting women and minors in harm's way, claiming that the migrants "encouraged conveniently invited media to begin filming their illegal acts".
CBP noted that its agents did not witness migrants, including children, experience the effects of the tear gas, which it said was "targeted at rockthrowers further away".
CBP added that an initial group of 150 migrants attempted to enter the US illegally by climbing over and under a fence, but 45 of them turned away.
The agency stated that teenagers wrapped in heady padding went over the fence's concertina wire, stating that the group also unsuccessfully attempted to transfer "toddler sized children".
Most of the migrants fled following the incident, while 25 were apprehended and taken into custody, including two teenagers.
"Unfortunately, Congress continues to ignore the professional advice from the men and women of the Border Patrol who have told them that walls work," Waldman said Tuesday.
Border experts have disputed that a concrete wall is the most efficient or cost effective form of border protection.
Many migrants in the caravan, which started in Honduras, are attempting to seek asylum in the United States.
The incident occurred amid an 11-day partial government shutdown centered around immigration and border protection.
President Donald Trump has demanded $5 billion to build a border wall, while Democrats refuse to increase previous levels of funding for border fencing.