BOSTON — Immigrant advocates in Boston say federal authorities are unfairly ordering foreign-born children granted special immigration status for medical treatment to return to their countries.

The Irish International Immigrant Center says it’s aware of at least five local families who have received notices this month to leave the U.S. within 33 days.

The families have “medical deferred action,” which enables them to receive government-funded health care and work legally while their children receive medical treatment.

U.S. Citizenship and Immigration Services says in letters sent to the families that the agency is no longer accepting deferred action requests. The only exception is for certain military members, enlistees, and their families approved by the U.S. Department of Homeland Security.

Advocates say similar notices have been recently issued in California, North Carolina and other states.