(TNND) — President Donald Trump declined Sunday night aboard Air Force One to say whether his administration violated a judge’s order when it flew alleged Venezuelan gang members out of the country under the Alien Enemies Act.

Trump referred the question to his administration’s lawyers.

“I can tell you this, these were bad people,” Trump added about the alleged Tren de Aragua gang members flown to a prison in El Salvador.

Trump invoked the Alien Enemies Act, a law that’s over 220 years old and has only been used a handful of times in the nation’s past, as the basis for deporting the gang members who had been designated as foreign terrorists.

White House press secretary Karoline Leavitt told reporters Monday that the administration “acted within the confines of the law” when it deported 137 people under the act, along with about 125 other immigrants this weekend.

Immigrant rights groups sued to stop the administration from deporting people under the Alien Enemies Act, and a U.S. district judge issued a hold Saturday on such deportations.

But some deportation flights were already en route when the judge issued his temporary restraining order.

The judge gave a verbal order to turn the planes around, but that directive wasn’t included in his written order.

Leavitt said the planes that were subject to the written order took off before the order was entered in the courtroom.

The Washington Post reported that two flights left Texas for El Salvador as the judge was reviewing the case and a third left shortly after a written order was issued. But the Post reported that it was unclear which of the flights included people subject to deportation under the act.

Trump’s proclamation said the Tren de Aragua gang members were operating in conjunction with Venezuela’s government to infiltrate the U.S. and conduct “irregular warfare” against Americans.

The administration said any Venezuelan Tren de Aragua gang member 14 or older who is in the U.S. illegally can be arrested and removed under the act.

Leavitt called the people covered by Trump’s order “heinous monsters” who “rape, maim and murder for sport.”

Secretary of State Marco Rubio said El Salvador has agreed to hold the alleged gang members “in their very good jails at a fair price that will also save our taxpayer dollars.”

UC Davis law professor Kevin R. Johnson said Trump is using the Alien Enemies Act in an “unprecedented” way.

“It's not a war,” said Johnson, an expert in immigration law and policy. “It's not an invasion as we standardly understand it. And he's pushing the limits of the law in apparent attempt to achieve outcomes and results that he wants.”

Much like the birthright citizenship question, Johnson said Trump’s interpretation of the Alien Enemies Act could end up before the Supreme Court.

“It was really designed to deal with nations we're at war with,” Johnson said. “We're not at war with Venezuela, and the executive order tries to concoct some legal theory that I'm not sure is going to pass muster with even a very conservative Supreme Court.”

Did the Trump administration violate the judge’s order by not turning around the deportation flights?

Johnson said that appears to be the case.

“The judge said don't fly anybody out, we got to do something now. And then they continued with the flight,” he said.

Johnson said it shouldn’t have mattered that the planes were already in the air or that the judge ordered the flights return orally and not in writing.

CNN reported Monday afternoon that the Justice Department submitted an argument that the oral order wasn’t enforceable as an injunction.