About 50 of the people traveling north through Mexico in a much publicized migrant “caravan” have arrived at the southwest border and have begun to apply for asylum, according to groups assisting them.

The migrants, who are mostly from Central American countries, arrived in the Mexican border city of Tijuana on Wednesday. A number of them have already crossed into the U.S. to petition for asylum, activists said.

“Since yesterday, some began to cross into the United States to turn themselves in from Tijuana and request asylum,” said Jose Maria Garcia, director of Juventud 2000, according to Reuters. “We understand more of (the migrants) will do the same.”

The caravan, which at one point numbered as many as 1,500 migrants, began its northward journey late March. Though it is an annual event, this year’s march gained prominence thanks to reports from U.S. media outlets describing the ways in which Mexican authorities were helping the migrants reach the U.S. border.

President Donald Trump reacted angrily to the news, accusing the Mexican government of facilitating illegal immigration and demanding that U.S. lawmakers act to tighten asylum laws. Later, he ordered a National Guard deployment to reinforce border agents.

Along its journey, the caravan dwindled as Mexican immigration authorities detained and deported some migrants who did not have a right to stay in Mexico. However, most of the caravan was allowed to continue, and several hundred migrants are expected to reach the border in the coming days.

“We will continue to receive them and it will be up to them if they stay in the country or leave,” Garcia said.

Under U.S. law, migrants who cross the border and are detained by Customs and Border Protection (CBP) can request asylum as “arriving” petitioners. If they pass an initial security screening, they are granted an interview with an asylum officer, who determines if the applicant has a “credible fear” of persecution in their home country.

Some of the migrants who arrived at the border on Wednesday are being denied the opportunity to apply for asylum, caravan organizers say.

“There have already been cases of people being illegally turned away by border officials when trying to request asylum at the U.S. border,” a spokesperson for Pueblo Sin Fronteras told Newsweek.

The Department of Homeland Security, which oversees U.S. immigration agencies, did not immediately respond to a request for comment on the arrival of asylum seekers.

Follow Will on Twitter

Send tips to will@dailycallernewsfoundation.org.

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.