Claiming the United States was being invaded by a Venezuelan gang, President Donald Trump on Saturday invoked the Alien Enemies Act of 1798, a sweeping war time authority that allows the president broader leeway on policy and executive action to speed up mass deportations of people — potentially pushing his promised crackdown on immigration into higher gear.

Trump invoked the Alien Enemies Act against Tren de Aragua members. A federal judge later ordered the administration to turn around any planes that had already taken off.

The judge’s initial temporary restraining order blocked the Trump administration from deporting five Venezuelans.