A federal judge on Monday temporarily blocked the Trump administration from using the 18th-century Alien Enemies Act to deport Venezuelan immigrants in Colorado, according to court records.

The American Civil Liberties Union sued President Donald Trump and multiple members of his administration in U.S. District Court in Denver on behalf of two Venezuelan men, referred to only by their initials, “and others similarly situated” who have been accused of being part of the Tren de Aragua gang, records show.

The organization said it was seeking “emergency relief on behalf of a class of all noncitizens in custody in the District of Colorado who were, are or will be subject to” Trump’s March proclamation titled “Invocation of the Alien Enemies Act Regarding the Invasion of the United States by Tren De Aragua.”

Trump said in his proclamation that “all Venezuelan citizens 14 years of age or older who are members of TdA, are within the United States and are not actually naturalized or lawful permanent residents of the United States are liable to be apprehended, restrained, secured and removed as Alien Enemies.”

While the litigation is pending, ACLU officials filed for a temporary restraining order so that no affected people can be removed from Colorado or deported during the proceedings.

U.S. District Judge Charlotte Sweeney approved the temporary restraining order Monday, blocking Trump and other federal officials from using the Alien Enemies Act for the next two weeks to remove plaintiffs D.B.U, R.M.M. and all other Venezuelan immigrants in Colorado accused of being members of Tren de Aragua from both the state and the country.

The Trump administration’s implementation of the Alien Enemies Act and the lawsuits that followed have become a flashpoint, escalating tension between the White House and federal courts.

D.B.U., a 31-year-old man who fled Venezuela after he was imprisoned for his political activity and protesting against the Venezuelan government, was arrested in January during a raid of what law enforcement and immigration officials have repeatedly called a “Tren de Aragua party” in Adams County.

The Drug Enforcement Administration said 41 people arrested that night were living in Colorado illegally and claimed dozens were connected to the TdA gang.

According to the ACLU, D.B.U. was identified as a gang member based on a tattoo of his niece’s name — his only tattoo. After his arrest, he “vehemently denied” being a TdA gang member.

The second man named in the lawsuit, 25-year-old R.M.M., fled Venezuela after two members of his family were killed by the TdA gang. ACLU officials said in the lawsuit he was afraid the gang would also kill him, his wife and his children.

R.M.M. was detained by immigration officials in March after federal agents saw him standing with other Hispanic men near their cars outside a Colorado residence that law enforcement believed was connected to the TdA gang, according to court records. Like D.B.U., R.M.M. was identified as a gang member based on his tattoos, including one of his birth year, one of his mother’s name, one of “religious significance” and a character from the Monopoly board game.

He is not and never has been a member of the TdA gang, ACLU officials wrote in court documents.

Trump invoked the Alien Enemies Act on March 14 in an attempt to grant himself wartime authority, “summarily remove noncitizens from the U.S. and bypass the immigration laws Congress has enacted,” ACLU officials stated in the lawsuit.

The ACLU claims Trump’s use of the act is invalid because the TdA gang is not a “foreign nation or government,” and there has been no “invasion or predatory incursion” — both of which are required to invoke the act.

“Criminal activity does not meet the longstanding definitions of those statutory requirements,” ACLU officials stated in the lawsuit. “Thus, the government’s attempt to summarily remove Venezuelan noncitizens exceeds the wartime authority that Congress delegated in the AEA.”

And even if Trump’s use of the act was lawful, ACLU officials said he’s still violating multiple important provisions in it.

“The government has still provided no meaningful notice, process or opportunity for individuals to challenge their designation as alien enemies, contrary to the AEA and due process,” ACLU officials stated in the lawsuit. “Removals under the Proclamation also violate the process and protections that Congress has prescribed for the removal of noncitizens in the immigration laws.”

The act also stipulates that people designated as “enemy aliens” will have time to “settle affairs” before removal and the option to voluntarily “depart.”

However, in a hearing in the Southern District of Texas on Friday, government officials said they had not ruled out the possibility that individuals will receive no more than a 24-hour notice. It’s possible they could receive even less.

In addition to Trump, the Colorado lawsuit names U.S. Attorney General Pamela Bondi, Secretary of the U.S. Department of Homeland Security Kristi Noem, Acting Director of U.S. Immigration and Customs Enforcement Todd Lyons, Secretary of State Marco Rubio, Director of the Denver Field Office for U.S. Immigration and Customs Enforcement Robert Gaudian and Denver Contract Detention Facility warden Dawn Ceja.

A hearing is scheduled in Denver on Monday to discuss the Colorado temporary restraining order and lawsuit.