Authorities in Eagle Pass are looking for two girls who were last seen walking in a park about a block away from their home.
The sisters, Dafne Perez, 7, and her older sister, Edna Mayline Perez, 9 had been staying with their grandmother after their father was killed in a car accident about three weeks ago.
The girls' uncle, Juan Perez, said the two sisters were at the grandmother's house on Wednesday when they snuck out of the back of the house while they had a babysitter there.
They were last seen by some construction workers at the park and that is where Perez believes his nieces were picked up.
Perez said their mother lives in Mexico and that his brother, the girls' father, was killed in a drunk driving accident three weeks ago.
He said their mother had been in jail before getting deported to Mexico.
"This is just a speculation," said Perez. "We don't know if the mom is involved in this or not, but if she is, let us know so that we know the girls are safe."
On Thursday, police released photos and descriptions of the two girls.
"It's a big concern," said Eagle Pass police Lt. Moises Pena. "That's why we have notified the FBI. The Texas Rangers are assisting us in our investigation. Also, we notified the National Center for Missing and Exploited Children."
If you have any information about the two sisters, you are asked to call the Eagle Pass Police Department at 830-773-9044.
Perez said since the girls ran off, they have not heard from the mother.