More police carrying plastic riot shields were on the other side, but migrants walked along the river to an area where only an earthen levee and concertina wire separated them from U.S. Border Patrol agents.
"We were told that if we crossed (the first barrier) they would give us asylum, because we were already in the United States", said Flor Jimenez, a 32-year-old Honduran woman who was among those who turned back along with her husband, sister and young daughter. "A large group rushed the area & were throwing rocks & bottles at my men & women, putting them in harm's way as well as other members of the caravan", Border Patrol wrote on Twitter on November 26.
"There were some press members who helped throwing water to the children and there was a child who was hardly breathing and a person from the press grabbed him and took him away", she said in Spanish.
Homeland Security Secretary Kirstjen Nielsen said in a statement that US authorities will continue to have a "robust" presence along the Southwest border and that they will prosecute anyone who damages federal property or violates USA sovereignty. "So some people got rocks and threw them because many kids were fainting", he said.
Around 1,000 Central American migrants held an initially peaceful rally in Tijuana, on the border with the United States, on Sunday.
Others pointed out that Obama's Border Patrol used force to repel violent would-be crossers.
Adrees Latif Reuters
"It is important to note that the fact the Mexican government protects their rights", the commission said, "does not imply a free pass to break the law". Many pointed to the children left gagging from the gas attack as evidence that Trump's push against a caravan of asylum seekers from Central America had gone too far.
After running to relative safety a few hundred feet away, hundreds of the caravan members held a sit-in. He has called for an additional 5,000 border patrol agents, yet Congress has failed to act on that. "My little girl is sick and I don't even have money for milk", said Joseph Garcia, 32, of Honduras.
Video released by the US Customs and Border Protection shows officers dressed in riot gear gathering near the auto lanes in San Ysidro. American authorities shut down the nation's busiest border crossing at San Ysidro for several hours at the end of the Thanksgiving weekend.
An average of 70,000 vehicles and 20,000 pedestrians cross from Mexico to the United States at San Ysidro each day, according to the U.S. General Services Administration.
Mexico's Interior Minister Alfonso Navarrete said on Monday that migrants who attempted to cross into the U.S. in a "violent way" would be deported.
Some 2,000 migrants participated, a Mexican federal police officer told The Epoch Times, while 39 migrants were arrested for causing fights and disturbing the public peace, according to a Mexican police spokesperson.
Parliament will stop a no-deal Brexit, insists Amber Rudd
"It does not appear there is a majority of MPs in the House of Commons that would vote for a no-deal Brexit outcome", he says. Rudd also cast doubt on May's plans to seal the Brexit deal on Sunday, saying that there are still obstacles in the way.