The first migrants from the much-publicized caravan that had been making its way through Mexico for the previous few weeks are now being processed, according to authorities.
The U.S. Customs and Border Patrol informed Mexico it could let in eight people from the group of 20 migrants who had taken up position outside the border access point in San Ysidro, California, according to the organizers of the caravan.
Caravan organizer Viridiana Vidal, from Pueblo Sin Fronteras, said agents rushed to the migrants camping outside, saying, "We are ready now."
Mothers and children were let in first, according to Vidal. Three mothers, four kids and one 18-year-old man, traveling alone, were let in, Vidal said.
The eight migrants were taken in at about 7:30 p.m. local time after waiting about 30 hours outside of the facility.
"As [U.S. Customs and Border Patrol] Commissioner [Kevin] McAleenan indicated yesterday, we reached capacity at the San Ysidro port of entry over the weekend, and were temporarily unable to bring additional persons traveling without appropriate entry documentation into the port of entry for processing," CBP said in a statement Monday night. "We began processing undocumented arrivals again on Monday. Depending upon port circumstances at the time of arrival, individuals presenting without documents may need to wait in Mexico as CBP officers work to process those already within our facilities."
Dozens more migrants nearby were waiting to be processed at the facility, which had said earlier Sunday, when they arrived, that the facility was too full to begin taking those seeking asylum in the U.S.
Delays are not unusual for asylum seekers at border crossings. A source who worked until recently at CBP and the Department of Homeland Security (DHS) told ABC News this port was often at capacity during President Barack Obama's administration as well.
Processing asylum seekers is not a quick process.
When an immigrant comes to a U.S. port of entry to request asylum, that person must declare to the customs officer a "credible fear of persecution" in his or her country of origin. Those seeking asylum are then moved to undergo a secondary interview with a different official to confirm that fear of persecution.
The asylum seeker will then be placed in a holding area before being transferred to a separate detention facility under Immigration and Customs Enforcement custody, while he or she awaits an adjudication hearing with U.S. Citizenship and Immigration Services, which will officially determine whether the asylum seeker can stay in the country.
Many of the migrants in the caravan had traveled through Central America and were from war-torn Honduras.
The Justice Department also announced charges on Monday evening against 11 members who they singled out as being "suspected members of the so-called 'caravan.'" CBP had announced on Sunday the capture of a number of people trying to illegally cross the border.
"When respect for the rule of law diminishes, so too does our ability to protect our great nation, its borders, and its citizens," Attorney General Jeff Sessions said in a statement. "The United States will not stand by as our immigration laws are ignored and our nation’s safety is jeopardized. U.S. Attorney Adam Braverman and his team should be commended for quickly filing illegal entry charges for individuals apprehended along the southwestern border."
The migrants will face illegal entry charges, the Department of Justice said. Those charged were arrested miles away from the California Port of Entry at San Ysidro.
Alex Mensing, an organizer with Pueblo Sin Fronteras, told ABC News' "Start Here" podcast on Monday he was unaware of any splinter groups of the caravan crossing the border: "If that has happened, we are not aware of it." Asked if he would support anyone taking matters into their own hands and just crossing the border he replied, "Absolutely not."
President Donald Trump has regularly railed against the caravan, especially on Twitter, dating back to a "Fox and Friends" report on the migrants on April 1. Trump equated the caravan with the country's need for a southern border wall, though the organizers of the group said the official asylum process was always their end goal.
Trump mentioned the caravan on Twitter for the first time the morning of April Fool's Day, saying on Twitter, "Mexico is doing very little, if not NOTHING, at stopping people from flowing into Mexico through their Southern Border, and then into the U.S."
He tweeted on Monday, prior to the CBP beginning the process of admitting asylum seekers, that the caravan was "openly defying our border" and it showed "how weak and ineffective U.S. immigration laws are." He criticized Sen. Jon Tester, D-Mont., in the tweet as well. Tester is a current target of the president over his treatment of Veterans Affairs secretary nominee Ronny Jackson.
Trump tweeted about the the U.S.-Mexico border 21 times in April, not including political endorsements for Tennessee Senate candidate Marsha Blackburn, Ohio Senate candidate Jim Renacci and Arizona state Senate candidate Debbie Lesko -- all of whom he touted as being strong on the border.
ABC News' Serena Marshall, Mike Levine and Joshua Hoyos contributed to this report.