As outrage continues over the Trump administration's controversial immigration policies, a group of celebs spent their Sunday (June 24) protesting in the border city of Tornillo, Texas.

Lena Dunham, Sia, Bella Thorne, Amber Heard, Connie Britton, and Constance Wu were among the stars who chartered a flight from Los Angeles to attend the protest, according to Buzzfeed News.

Dunham — who held a sign that read "#KeepFamiliesTogether" — shared a group pic of some of the celebs in attendance. She wrote, "We came to Tornillo, Texas, to show our solidarity with the families who have been separated, the children who are alone, the parents who are grieving, and the undocumented Americans who are losing more than I can fathom. Thank you, Tornillo, for showing us a warm border welcome and reminding us that together we rise."

Sia shared her own pic with Dunham and asked her fans to donate to Voto Latino, a nonprofit aiming to get Hispanic voters to the polls. The generous singer said she would match all donations up to $100,000.

Meanwhile, married Pitch Perfect stars Skylar Astin and Anna Camp passionately protested together, while Heard shared a photo of her own sign, which read, "Apartheid was legal. Holocaust was legal. Legality is a matter of power, not justice."

The protest in Tornillo comes amid outcry over the Trump administration's "zero tolerance" immigration policy. Last Wednesday, President Trump signed an executive order to reverse his policy of immigrant family separations, though the Departments of Homeland Security and Health and Human Services revealed on Saturday that 2,053 children were still in the custody of HHS and were awaiting being returned to their parents.

To learn more about how you can support immigrant families, visit familiesbelongtogether.org.