Democrats in Congress have launched an investigation into the Trump administration’s detention of the family members of more than 50 active-duty troops as part of its deportation efforts, a departure from previous policy that protected families from immigration enforcement, according to a new report.

More than 60 House and Senate members signed on to a letter sent on Sunday evening to the departments of homeland security, war, and veterans affairs, stating plans to investigate whether the DHS and Pentagon are working together to target service members and their families.