MEXICO CITY — A peaceful march by Central American migrants waiting at the southwestern United States border veered out of control on Sunday afternoon, as hundreds of people tried to evade a Mexican police blockade and run toward a giant border crossing into California.
In response, the United States Customs and Border Protection agency shut down the border crossing in both directions.
The march in Tijuana, Mexico, was met by Mexican federal police officers at a bridge that leads to the San Ysidro border crossing, through which millions of people and vehicles pass each year. At that point, some of the migrants tried to go around the police by running across a dry riverbed.
The police, carrying anti-riot shields, then formed a new line and appeared to contain the rush of migrants 100 yards or more from the crossing. They erected metal barriers on the roads and sidewalks leading to the crossing.
A group of migrants then tried to make their way to the train crossing, where they were met by police officers who released tear gas to stop them.
The unrest came as Mexico is trying to deal with thousands of Central American migrants who have arrived in Tijuana in an attempt to either seek asylum or, in some cases, cross the United States border illegally.
The migrants have spent the past 10 days in squalid conditions in a community sports center that has been converted into a makeshift shelter. Many have become increasingly desperate with the realization of the obstacles still before them in reaching the United States.
Tijuana city officials say they have no money to improve conditions at the sports center, where an estimated 5,000 migrants are sheltering.