By TIM SULLIVAN AND ELLIOT SPAGAT, Associated Press

The U.S. deported hundreds of immigrants after President Donald Trump invoked the Alien Enemies Act for the first time since World War II, using the sweeping powers of a centuries-old wartime law to target alleged members of a Venezuelan gang. The deportations over the weekend came as a federal judge issued an order temporarily barring them.

The act gives allows noncitizens to be deported without the opportunity to go before an immigration or federal court judge. Trump’s Saturday proclamation called the Tren de Aragua gang an invading force.

The administration has not identified who was deported, provided any evidence they are gang members or that they committed any crimes in the United States.

The Tren de Aragua gang originated in Venezuela, but the deportees were sent to El Salvador after the Trump administration agreed to pay $6 million for 300 alleged members to be imprisoned there for a year. Venezuela typically does not agree to accept its citizens deported by the U.S., though it has done so on a few occasions. The U.S. also sent back two top members of the Salvadoran MS-13 gang to El Salvador.

U.S. District Judge James E. Boasberg, who was appointed by President Barack Obama, issued an order temporarily blocking the deportations, but lawyers said two planes with immigrants were already in the air. Boasberg then verbally ordered the planes be turned around, but the flights continued.

Trump repeatedly said during his campaign that he would use extraordinary powers to confront illegal immigration and laid additional groundwork in a slew of executive orders since his return to office.

What is the Alien Enemies Act?

In 1798, with the U.S. preparing for what it believed would be a war with France, Congress passed a series of laws that increased the federal government’s reach. The Alien Enemies Act was created to give the president wide powers to imprison and deport noncitizens in time of war.

Since then, the act has been used just three times: during the War of 1812, World War I and World War II.

It was part of the World War II legal rationale for mass internments in the U.S. of people of German, Italian and especially Japanese ancestry. An estimated 120,000 people with Japanese heritage, including those with U.S. citizenship, were incarcerated.

What brought this to a head on a Saturday?

The American Civil Liberties Union and Democracy Forward preemptively sued Trump late Friday saying five Venezuelan men held at a Texas immigration detention center were at “imminent risk of removal” under the Alien Enemies Act. Boasberg blocked their deportation, prompting an immediate Justice Department appeal.

Almost simultaneously, the Trump administration agreed to the payment to El Salvador, where the government of President Nayib Bukele has arrested more than 84,000 people, sometimes without due process, in a crackdown on gang violence, often sending suspects to a notorious mega-prison.

The U.S. isn’t at war, is it?

For years, Trump and his allies have argued that the U.S. is facing an “invasion” of people arriving in the country illegally.

Arrests on the U.S. border with Mexico topped 2 million a year for two straight years for the first time under President Joe Biden, with many released into the U.S. to pursue asylum. After hitting an all-time monthly high of 250,000 in December 2023, they dropped sharply in 2024 and even more after Trump took office, reaching less than 8,400 in February — the lowest level since the 1960s.

Administration officials use military terminology to describe the situation. In his Saturday declaration, Trump said Tren de Aragua “is perpetrating, attempting, and threatening an invasion or predatory incursion” against U.S. territory.

On Sunday he went further when speaking to reporters on Air Force One, saying: “This is a time of war.”

Critics say Trump is wrongly using the act.

“The Alien Enemies Act may be used only during declared wars or armed attacks on the United States by foreign governments,” The Brennan Center for Justice said in a Saturday statement. “The president has falsely proclaimed an invasion and predatory incursion to use a law written for wartime for peacetime immigration enforcement.”

Associated Press writer Regina Garcia Cano in Caracas, Venezuela, contributed to this report.