A Brownsville mother read letters written by children detained at an immigration processing center in Dilley.

It’s part of a movement to give a voice to the children at the South Texas Family Residential Center.

Lemy Martinez recorded herself reading a letter from Mia Valentina Paz Faria, a 7-year-old from Venezuela. The girl wrote, "I don't want to be in this place, I want to go to my school. I miss my grandparents. I miss my friends."

Martinez is one of hundreds of mothers who read a letter on Thursday as part of the 10,000 Letters from Dilley campaign organized by the national group Mothers Forward.

"These facilities are for criminals, and they're not criminals," Martinez said of the children. "At the end of the day they are children, someone's children; they could be my children, and that's not a way of living."

The campaign is working with the Rio Grande Valley group Blue Bunny Brigade. Martinez is a founding partner of the local group.

Martinez said she joined after hearing about Liam Cornejo Ramos, the 5-year-old boy from Minnesota who was detained by U.S. immigration agents in January.

"The time limit that most of these families should be detained is 20 days, and they have been detained for much longer," Martinez said. "70 days for Mia, 100 days for a lot of these other children — that's a lifetime for kids."

As a mother, Martinez said she is concerned about the long-term mental, physical, and emotional health of the children housed in immigration centers.

The group is asking for the children to be released by Mother's Day. A caravan will leave from the Rio Grande Valley on April 19 to the Dilley detention center to protest the detainment of children.

Watch the video above for the full story.