Some active duty service members detained as part of DEA operation at underground nightclub Colorado Springs

COLORADO SPRINGS, Colo. — Some active duty military service members were among those detained during a large-scale federal law enforcement operation Sunday morning at an underground nightclub in Colorado Springs, the Drug Enforcement Administration said.

More than 300 law enforcement officers from at least 10 federal agencies, including the DEA, FBI and Homeland Security, were involved in the operation, according to DEA Special Agent in Charge Jonathan Pullen.

The operation, which began around 3 a.m. Sunday, was part of an investigation into drug trafficking, prostitution and crimes of violence at the illegal club. In total, more than 100 people were detained, the DEA said.

More than a dozen active duty service members were at the underground nightclub, either as patrons or working as security, Pullen said. The Army confirms that service members from its base in Fort Carson were present. However, they will not say how many service members were involved.

The United States Army Criminal Investigation Division released the following statement:

“Army CID is aware of this matter and is currently conducting a joint investigation with the Drug Enforcement Administration (DEA), which is the lead agency. As this is an ongoing investigation, we are unable to provide additional information at this time,” the statement read.

• WATCH: DEA Special Agent in Charge Jonathan Pullen joins Denver7 News live to describe how the investigation and operation unfolded

Pullen said gang members, including Tren de Aragua and MS-13, have a history of operating at the club. It was unclear how many, if any, gang members may have been present Sunday.

"Colorado Springs is waking up to a safer city this Sunday morning," he said.

Officers were seen escorting people from the club in handcuffs, according to the Denver7 Investigates crew at the scene. Law enforcement had cordoned off several square blocks around the club in central Colorado Springs to conduct the operation.

The DEA's Rocky Mountain Division said in a social media post that more than 100 people in custody were in the U.S. illegally.

The agency said it seized drugs and weapons during the operation.

Pullen said that many of those detained will face federal immigration charges, and some were arrested on outstanding warrants. Still, he said it is unlikely they will be able to file drug charges because of the difficulty in proving possession during the bust.

• Watch: Denver7 Investigates' Natalie Chuck and Tony Kovaleski report from the scene

The owner of the building, Mike Moon, expressed shock after learning that his property was allegedly being used as an illegal nightclub.

“I've never even seen a lot of trash in the parking lot to even suspect that anything like an after-hours nightclub is going on. So, it's pretty shocking,” Mike Moon, the owner of the property, said.

In a statement, Colorado Springs Mayor Yemi Mobolade thanked law enforcement and said criminal activity will not be tolerated.

“Let me be clear: criminal activity of any kind, from anyone, will not be tolerated in Colorado Springs. This investigation and the execution of these warrants are the result of clear evidence of serious criminal conduct. Our residents deserve to live in a city where the rule of law is upheld and where illegal behavior is met with firm and decisive action. We will continue working together to ensure the safety and well-being of our entire community.”

In a statement to Denver7 Investigates early Sunday, Colorado Springs police said they were "assisting federal partners on an operation serving a warrant involving criminal activity in Colorado Springs" and that the DEA was the lead agency.

This is a developing story and will be updated as we learn more.

‘Ground zero’ for violent criminals

Sunday’s operation, which appears to be the first large, coordinated federal operation of its kind in El Paso County this year, comes amid a Colorado crackdown by the DEA.

As the agency conducted four Denver-area operations on Jan. 29, special agent in charge David Olesky said an uptick in enforcement is due to a “renewed sense of purpose” at the agency under the Trump administration.

“We’re getting absolutely all the resources that we need not only at the federal level but at the local level as well,” he said at the time. “And when it comes to immigration, that is just one of the tools in the toolbox that we’re going to be able to use to remove those violent criminals and drug traffickers from the communities.”

Derek Maltz, who stepped into the role of acting administrator of the DEA shortly after President Trump’s inauguration, told Denver7 Investigates that Colorado is “ground zero” for violent criminals in the U.S. and that the state is home to the “command and control” of the Venezuelan gang Tren de Aragua.

• Watch that story, in the video player below:

He said he believes criminals have taken advantage of vulnerabilities and weaknesses in the state, and that the border policies of recent years have been too open and allowed for too many people to cross the U.S. border unaccounted for.

“We love immigration. It makes this country great. Diversity is critical to the success of America. But we have to have a system," he said.

The DEA has faced obstacles

While the agency touted more than 90 arrests over 12 Colorado operations in less than three weeks between late January and early February, the DEA admitted to Denver7 Investigates that it expected more. A multi-city federal operation on Feb. 5 targeted more than 100 members of TdA but netted just one confirmed TdA arrest.

Jonathan Pullen, a DEA special agent in charge, said he believes the targeted criminals were feeling the pressure.

“What we found was that they weren't where we expected them to be," he said. “It's likely that the pressure that we've put on these folks over the last several weeks has encouraged them to hide more.”

• CONTEXT: Trump’s “border czar” said leaks from local media outlets blew the feds’ cover. Immigrant rights advocates told Denver7 it was just a matter of preparedness.

But in some cases, like Sunday's operation in Colorado Springs, even those who have been arrested haven’t been punished – particularly in drug cases.

An event billed as a “TdA invite-only party” in Adams County netted 49 arrests, but none of the suspects ended up facing charges. Pullen said drugs and guns "hit the floor" when officers arrived, making it difficult to pinpoint what individuals they may have belonged to.