Mexico will deport up to 500 migrants who attempted to storm the US border, according to its interior ministry.
The group were rounded up after trying to cross the border “violently” and “illegally” on Sunday, the ministry said in a statement.
Video footage shows dozens of people – including women and children – running towards the fence that separates the two countries near the city of Tijuana.
They were repelled by tear gas used by US border officers.
Mexico’s interior ministry said in a statement that a group of “nearly 500 migrants” had “tried to cross the border in a violent way”.
Those identified as having taken part in these “violent events” would be deported immediately, it said.
The ministry added that, “far from helping their objectives”, the migrants’ actions had violated the legal migration framework and could have led to a “serious incident”.
Tensions have been high in Tijuana since the arrival of thousands of migrants earlier this month.
The migrants are in Tijuana after travelling more than 4,000km (2,500 miles) from Central America.
They say they are fleeing persecution, poverty and violence in their home countries of Honduras, Guatemala and El Salvador.
However, they now face a long wait to see if their asylum applications will be accepted by the US, with President Donald Trump vowing to keep each migrant on the Mexican side of the border until courts have decided their case. This could take months.
Amid growing desperation on Sunday, the group of about 500 migrants were taking part in a peaceful protest for the right to seek political asylum in the US.
“We aren’t criminals! We are hard workers,” they chanted.
Mexico’s Home Secretary, Alfonso Navarrete, said the group had asked for help to organise the demonstration, but were then reportedly encouraged by some of the movement’s leaders to split into different groups so they could make a run for the border and try to cross into the US.
Mr. Trump threatened to close the entire US-Mexico border earlier this week if it was felt the US was going to “lose control” of the situation.
He also said he had given troops at the border the go-ahead to use lethal force if needed.
Mr. Trump has deployed about 5,800 troops to the border. He previously