US authorities fired tear gas into Mexico during the first hours of the new year to repel about 150 migrants who were trying to breach the border fence in Tijuana.
The people affected by the gas included women and children, as well as members of the press.
US Customs and Border Protection said in a statement, the gas was used to target rock throwers apart from the migrants who were trying to cross.
Customs and Border Protection said that under its use of force policy the incident would be reviewed by its Office of Professional Responsibility.
Many of the migrants are waiting in Tijuana for a chance to apply for asylum in the US, but there was a backlog before the caravan’s arrival and the wait is expected to be many months. Others have found jobs in Mexico and tried to settle there.