Mexican police officers reportedly escorted the remnants of the once 1,200-person “migrant caravan” from shelters in Tijuana, Mexico, to the San Ysidro, California, port of entry. Hundreds of mostly Central American migrants plan to cross the border within the next few hours while others contemplate staying in Mexico. Some have already illegally crossed the border into southern California.

Mexican police officers could be seen in a CBS News video escorting buses of Central American migrants from the shelters where they spent the past few days to the country’s northern border with California. Some of the prospective border crossers expressed nervousness as they prepare to face U.S. officials for the first time.

Some of the migrants decided not to try a legal entry and jumped a border fence in disrepair to illegally enter the U.S. They were quickly met by U.S. Border Patrol agents who placed them in custody, Breitbart News Joel Pollak reported on Sunday.

“In several of these incidents, children as young as 4-years-old, and in one case a pregnant female, were detected entering the United States illegally through a dark, treacherous canyon that is notorious for human and drug smuggling,” San Diego Sector Chief Patrol Agent Rodney Scott said in a written statement.

Immigration lawyers told the migrants to prepare for possible separation for their families for several months, the CBS News report states.

“We are the bearers of horrible news,” Los Angeles lawyer Nora Phillips said after briefing migrants in three workshops. “That’s what good attorneys are for.”

U.S. Department of Homeland Security (DHS) Secretary Kirstjen Nielsen issued a stern warning to attorneys and immigrant activists about coaching migrants on how to circumvent immigration law or fraudulently apply for asylum status, Breitbart Texas reported. “If you assist or coach an individual in making a false immigration claim, you have broken the law and will be referred for prosecution,” the DHS secretary stated.

Sunday morning, members of the “migrant caravan” arrived at Friendship Park in Tijuana in preparation for their march to the border. Demonstrators lined both sides of the border in anticipation, CNN reported.

In what could possibly lead to the prosecution of the migrants, many could be seen getting “married” before making the crossing into southern California, Breitbart News Katherine Rodriguez reported.

There are four couples from the caravan getting married. pic.twitter.com/kK69BwtYip — Adolfo Flores (@aflores) April 29, 2018

“Several migrant couples who showed up at the border between Tijuana, Mexico, and San Diego, California, married each other Sunday morning in a small ceremony presided over by a Chicago pastor with ‘monarch butterfly wings,” Rodriguez wrote.

The article continues:

The couples tied the knot before reportedly presenting themselves to United States authorities at the San Ysidro point of entry Sunday after legal counsel for the migrants informed them they could be separated from their children and detained for months. But these “marriages” might not work for these migrants because U.S. immigration courts require substantial proof to prove that a marriage is real. When migrants typically apply for asylum, immigration authorities require proof beyond a ceremony and a marriage certificate that the couple married intending to start a life together. Under U.S. immigration law, if authorities suspect a couple recently married to obtain a green card or for the purposes of immigration into the United States, the marriage is considered fraudulent and can be disregarded by immigration courts when deciding to allow foreigners into the United States.

Many migrants could be seen climbing to the top of border fences while U.S. Border Patrol agents maintained their watch, CNBC reported Sunday afternoon.

People scale border fence in Tijuana as migrant caravan prepares to seek asylum in U.S. https://t.co/usIX6vNlW3 pic.twitter.com/Vas2CdwcTw — #NBC7 San Diego (@nbcsandiego) April 29, 2018

The migrants are expected to begin crossing the border early afternoon on Sunday, the New York Times reported.