The busiest and largest border checkpoint on the U.S.-Mexico border, San Ysidro port of entry, was shut down by U.S. Customs and Border Protection agents Sunday after hundreds of migrants from the caravan stormed the checkpoint attempting to breach a U.S.-Mexico border fence.

“This AM, @CBP was forced to close the #SanYsidro POE to ensure public safety in response to a large # of migrants seeking to illegally enter the US. They attempted to breach legacy fence infrastructure along the border and sought to harm CBP personnel by throwing projectiles @ them,” Nielsen said on Twitter Sunday evening.

“@DHS will not tolerate this type of lawlessness & will not hesitate to shut down POEs for security reasons. We’ll seek to prosecute to the fullest extent of the law anyone who destroys federal property, endangers our frontline operators, or violates our sovereignty.”

President Trump said Saturday that migrants would be made to stay in Mexico while awaiting the results of asylum claims.

Migrants at the Southern Border will not be allowed into the United States until their claims are individually approved in court. We only will allow those who come into our Country legally. Other than that our very strong policy is Catch and Detain. No “Releasing” into the U.S…

— Donald J. Trump (@realDonaldTrump) November 24, 2018

….All will stay in Mexico. If for any reason it becomes necessary, we will CLOSE our Southern Border. There is no way that the United States will, after decades of abuse, put up with this costly and dangerous situation anymore!

— Donald J. Trump (@realDonaldTrump) November 24, 2018

Breitbart reports:

CBP officials closed traffic roads moving in both directors and pedestrian walkways at the port of entry. An Associated Press reporter said tear gas was fired at the migrants from inside the U.S.

Hundreds try to storm the border. Expect significant US response #tijuana pic.twitter.com/0T50XUnXtY

— emma murphy (@emmamurphyitv) November 25, 2018

https://twitter.com/WendyFry_/status/1066773189370552320?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1066773189370552320&ref_url=https%3A%2F%2Fwww.breitbart.com%2Fimmigration%2F2018%2F11%2F25%2Fsan-diego-port-entry-shut-down-migrants-rush-border-chanting-yes-we-can%2F

#BREAKING: Lanes and pedestrian crossings close at San Ysidro Port of Entry amid border marches. https://t.co/11cUSvrzrp pic.twitter.com/N42EADvaEx

— #NBC7 San Diego (@nbcsandiego) November 25, 2018

https://twitter.com/WendyFry_/status/1066791682899959808?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1066791682899959808&ref_url=https%3A%2F%2Fwww.breitbart.com%2Fimmigration%2F2018%2F11%2F25%2Fsan-diego-port-entry-shut-down-migrants-rush-border-chanting-yes-we-can%2F

U.S.-Mexico border near Tijuana closed as migrants attempt to breach fence:

“Some of these migrants attempted to breach legacy fence infrastructure…and sought to harm CBP personnel by throwing projectiles at them,” DHS Sec. Nielsen said in a statement. https://t.co/YP5cIFX5KZ pic.twitter.com/U0voEg1yAs

— ABC News (@ABC) November 25, 2018

In one video shared by ITV reporter Emma Murphy, migrants are heard shouting “yes we can” as they rush the entry point.

Some pushing right to fence shouting “yes we can”. pic.twitter.com/m03bNX9LIk

— emma murphy (@emmamurphyitv) November 25, 2018

U.S. Border Patrol helicopters flew overhead, while U.S. agents held vigil on foot beyond the wire fence in California.

Military helicopters are flying over the border as @CBPSanDiego agents in riot gear block the roadway pic.twitter.com/OCG0lQfexo

— Ramon Galindo (@RamonGalindoNBC) November 25, 2018

More than 5,000 migrants have been camped in and around a sports complex in Tijuana after making their way through Mexico in recent weeks via caravan. Many hope to apply for asylum in the U.S., but agents at the San Ysidro entry point are processing fewer than 100 asylum petitions a day.

A second line of Mexican police carrying plastic riot shields stood guard outside a Mexican customs and immigration plaza, where the migrants were headed.

That line of police installed tall steel panels behind them outside the Chaparral crossing on the Mexican side of the border, which completely blocked incoming traffic lanes to Mexico.

Hours after the attempted breach, Homeland Security Secretary Kirstjen Nielsen issued the following statement:

“After being prevented from entering the Port of Entry, some of these migrants attempted to breach legacy fence infrastructure along the border and sought to harm CBP personnel by throwing projectiles at them. As I have continually stated, DHS will not tolerate this type of lawlessness and will not hesitate to shut down ports of entry for security and public safety reasons,” the statement continued. “We will also seek to prosecute to the fullest extent of the law anyone who destroys federal property, endangers our frontline operators, or violates our nation’s sovereignty.”

DHS Sec. Nielsen issues statement on San Ysidro Port of Entry closure: “As I have continually stated, DHS will not tolerate this type of lawlessness and will not hesitate to shut down ports of entry for security and public safety reasons.” https://t.co/qityKL6n9A pic.twitter.com/4eDIgMbNIr

— ABC News (@ABC) November 25, 2018

Tijuana Mayor Juan Manuel Gastlum on Friday declared a humanitarian crisis in his border city of 1.6 million, which he says is struggling to accommodate the crush of migrants.