Three US citizen children were deported to Honduras with their mothers last week, including a 4-year-old receiving treatment for metastatic cancer, according to the families’ attorneys and civil rights and immigration advocacy organizations.

Secretary of State Marco Rubio defended the deportation of three children who are U.S. citizens, claiming the mothers could have made their kids stay behind. “Those children are U.S. citizens,” Rubio said on Sunday’s episode of “Meet The Press.

The removals of three young U.S. citizens have intensified concerns about whether the Trump administration is violating the rights of citizens and noncitizens.