Three children who are all U.S. citizens were held for several hours by Customs and Border Protection officers at a Chicago airport on Thursday morning in what activists say was a bid to lure their undocumented parents into custody, The Chicago Tribune reports. The children, ages 9, 10 and 13, were held at O'Hare International Airport after they returned from a trip to Mexico with a relative whom CBP officials deemed “inadmissible.” They reportedly told their mother officials wouldn't release them unless their undocumented parents picked them up. Their mother, Sylvia, was fearful she would be detained so she sent her son and daughter-in-law to pick them up, but they were turned away by officials. Sylvia then called the Mexican consulate, and an official was able to negotiate a deal where she could pick the children up without fear of being taken into custody herself. The relative was reportedly sent back to Mexico.

CBP confirmed the children were stopped because the adult they were traveling with was not allowed to enter the U.S. and said the agency “attempted numerous times today to reach family members to pick up the children.” Activists reportedly protested the children’s detention at the airport, and lawmakers also spoke out about the issue. “I feel that it’s a kind of kidnapping of children by our government, and I’m really fed up with what we are doing,” Rep. Jan Schakowsky (D-IL) told the newspaper.