Updated at 10:50 a.m. Monday with details from police about arrests.

Diana and Pamela Rubio know what family separation feels like.

The sisters were just 10 and 13 years old when they immigrated with their father to the United States from Durango, a city in northwest Mexico.

They were allowed to stay under Deferred Action for Childhood Arrivals, but two years ago their father was deported back to Durango — and the women haven't seen their grandparents, aunts or uncles in more than 10 years.

The Rubio sisters joined an estimated 2,500 demonstrators Saturday at Dallas City Hall to protest the separation of immigrant families at the U.S.-Mexico border.

"We know what it feels like not being able to touch them," said Diana Rubio, 25. "When you talk through the phone to them, you can barely even hear. We can only imagine what a kid is going through."

From Dallas to Washington, D.C., thousands participated in Families Belong Together rallies and marches. At the Dallas event, which started at 10 a.m., representatives from the Democratic Party helped people register to vote and write letters to their legislators.

The Dallas event's organizer, Michelle Wentz, said all were welcome at the march because its intent was to unify people across the political spectrum, not to divide them.

"I've talked to people on both sides, and 70 percent are of the same mind-set," she said. "This is not a partisan rally or march."

1 / 7Protesters march past the bronze cattle heard in Pioneer Plaza during the Keep Families Together rally Saturday.(Tom Fox / Staff Photographer) 2 / 7Protesters joined hands in solidarity during the downtown rally Saturday.(Tom Fox / Staff Photographer) 3 / 7Guest speaker Alona Kemp weeps as she reads her speech for those gathered at Saturday's rally at Dallas City Hall.(Tom Fox / Staff Photographer) 4 / 7Actress and activist Cheryl Allison spoke during the Keep Families Together rally at Dallas City Hall in downtown Dallas on Saturday. Her jacket's message was intended to mock one worn by Melania Trump when the first lady visited the border.(Tom Fox / Staff Photographer) 5 / 7Lily Schmitt of Allen uses a tube of lipstick to finish her protest sign Saturday.(Tom Fox / Staff Photographer) 6 / 7Thousands march down Young Street on Saturday during a rally at Dallas City Hall in downtown Dallas. (Tom Fox / Staff Photographer) 7 / 7A child holds a protest sign Saturday during the Keep Families Together rally at Dallas City Hall.(Tom Fox / Staff Photographer)

In early April the Trump administration announced a zero-tolerance policy, meaning that every immigrant who illegally crossed the U.S.-Mexico border, asylum-seekers included, would be criminally prosecuted.

More than 2,000 immigrant children — too young to be prosecuted — were separated from their parents and placed into federal custody before President Donald Trump signed an executive order June 20 halting family separation at the border.

While the demonstrators marched downtown, about 80 protesters in Dallas rallied outside the U.S. Immigration and Customs Enforcement building off Stemmons Freeway.

A police supervisor at the scene told KXAS-TV (NBC5) that the demonstration got off to a peaceful start but became unruly when protesters blocked the highway service road and one man sat down in traffic.

Police asked them to move twice and arrested five people when they didn't comply. Four of them — Alexis Estrada, 32; Christopher Goode, 30; Robert Helmick, 27; and Savanna Batten, 25 — face charges of obstructing a highway.

Lauren Bourdignon, 29, was charged with assault on a public servant, obstructing a highway and interfering with public duties. Police said Bourdignon pulled the arm of one of her fellow protesters in an attempt to stop an arrest and elbowed an officer in the face, leaving a cut on the officer's nose.

From left: Lauren Bourdignon, Christopher Goode, Alexis Estrada, Robert Helmick, Savanna Batten. (Dallas County Sheriff's Department)

None of the five remained in custody Monday morning, jail records indicated.

Before the march got under way downtown, the crowd listened to a long list of speakers, including state Rep. Victoria Neave, D-Dallas, and Dallas County Judge Clay Jenkins.

One notable speaker was Cheryl Allison, a former Broadway actress and activist who spent four days volunteering at a respite shelter in McAllen. Allison wore a fake Zara jacket akin to the one first lady Melania Trump wore when boarding a plane to visit a children's shelter in Texas. The version of the jacket Allison wore Saturday sported white letters that spelled: "I really DO care, don't u?"

Allison talks about her trip to McAllen, Texas, where she volunteered through a Catholic charity to help refugees contact family members in the U.S. She said she recognized some of the families she helped in @dallasnews photographs by @SmileyPool. pic.twitter.com/zSJ62FQwO4 — Samantha J. Gross (@samanthajgross) June 30, 2018

"This is not a political issue," she said in an interview. "This is a humanitarian issue. And we have to restore human dignity."

Another speaker, college student Alona Kemp, gave an emotional address invoking the phrase "e pluribus unum," or "out of many, one."

The march went to the Kay Bailey Hutchison Convention Center and circled back to City Hall.

Police at the scene said no counterprotests had been planned for Saturday.

Turn around in the tunnel under the convention center. Voices echo “no justice, no peace.” #FamiliesBelongTogether pic.twitter.com/XSagAkBtIi — Samantha J. Gross (@samanthajgross) June 30, 2018

One marcher wore a visor with colorful letters spelling "family" and marched while wrapped in a foil blanket.

"This is is what they give the children to comfort them," said Mary Garcia, 47, of Dallas. "As you can see, it does nothing except keep them awake with the noise and remind them that they're not together with their family."

Another marcher wore a garland made of children's shoes around his neck.

"This is a symbolic reaction of mine," said Isabelo García, 56, of Rockwall. "These young children are lost, without anyone helping them out."

1 / 5From left: Leticia Salinas of Garland, Mary Garcia of Garland and sister Rosa Hernandez of Corinth covered themselves with Mylar blankets, similar to those given to immigrant children at the border.(Tom Fox / Staff Photographer) 2 / 5Guest speaker Alona Kemp (left) is comforted by march organizer Michelle Wentz as she broke down following her emotional speech at the Dallas rally.(Tom Fox / Staff Photographer) 3 / 5Protesters are reflected in the windows of the Kay Bailey Hutchison Convention Center during the Keep Families Together march in Dallas.(Tom Fox / Staff Photographer) 4 / 5A protester waves the Mexican flag during Saturday's rally in Dallas.(Tom Fox / Staff Photographer) 5 / 5Ashley Washington of Dallas (right) and Alma Martinez of Dallas chant with protesters during Saturday's rally in downtown Dallas.(Tom Fox / Staff Photographer)

More than 625 events were planned this weekend across all 50 states, as well as in Puerto Rico and the U.S. Virgin Islands, to "send a clear message to Donald Trump and Republicans in Congress," according to Families Belong Together — a coalition of advocacy groups including the American Civil Liberties Union, MoveOn and the Women's March.

Wentz said she has kept her activism private until now.

"It's something that I couldn't just sit idly by," she said. "I want to be a catalyst to get the message out there that we're not going to tolerate any form of this policy."