Despite vowing "zero releases," the Trump administration has begun quietly releasing dozens of immigrant families from a Texas detention center after detaining but not deporting them.

U.S. Immigration and Customs Enforcement released some 160 detained people – half of them minors – to a border shelter beginning Jan. 17, with plans to release as many as 100 to 150 per day over the next two to three weeks, according to the shelter director and other sources with direct knowledge of the releases.

The reason for the releases remains unclear, but the families hail from nearly a dozen countries including Iran, Russia, China, Vietnam, Venezuela, Guatemala and Mexico.

The sudden releases run counter to President Donald Trump's mass deportation campaign, which seeks to remove millions of immigrants living in the country illegally.

Pastor Mike Smith of the nonprofit Holding Institute, a shelter affiliated with the United Methodist Church and United Women in Faith, received the families on Saturday, Jan. 17, and Monday, Jan. 19, in Laredo, Texas.