Over 400 migrants with ISIS ties released at border because they weren't on terror watchlist: Report

The U.S. government released more than 400 migrants brought to the U.S. border by an ISIS-affiliated human smuggling network because they weren’t on the terrorist watchlist.

A Department of Homeland Security official said that 150 have been arrested but the whereabouts of 50 across 17 states are unknown, according to NBC News.

It is unclear exactly how many of the 150 who were arrested have been deported. An official told NBC News some of the 150 were deported.

Some of the migrants with ISIS ties "may have already left the U.S. voluntarily," according to the report.