Law enforcement officers on Monday raided more than two dozen residences and businesses, charging 18 people with conspiring to sell heroin and cocaine out of a townhouse community in Montgomery County and a music studio in Prince George’s County.

Most of those charged, 14, were linked to what officials called an open-air drug market in and around the Bel Pre Square development in Montgomery, officials said. The investigations lasted a year and included wiretaps. Officials said they put the organization out of business.

In transcripts of recorded calls, parts of which were included in court papers made public Monday, authorities said the suspects talked about their dealing.

“I’m a have that cheese for you tomorrow,” a caller said on Feb. 19 while speaking to George Earl Gee, 37, described by authorities as the leader of the Bel Pre Square operation, according to federal court records.

Text messages also were intercepted, including from one of Gee’s associates who was complaining to Gee, of Beltsville, about using cellphones to discuss their drug business.

“I jus don’t understand why we hav to go threw all this extra conversation on the phone u know our routine,” texted the associate, Anthony Niles, according to court papers. “u have to understand this phone s--- dangerous.”

The drug operation in Bel Pre Square had grown large enough to draw customers from throughout Montgomery and neighboring counties, officials said. The organization posted lookouts to warn their dealers when police were possibly approaching.

Assistant Montgomery Police Chief Russell Hamill said the number of raids conducted Monday was the most he has known to take place in Montgomery at one time. “This is unprecedented,” he said.

He said that the raids started before sunrise and involved more than 100 local, state and federal officers.

Officials said that the raids involved numerous residences in the Bel Pre Square area.

“We eliminated that group,” said FBI Special Agent Stephen Vogt, head of the bureau’s Baltimore field office. “They no longer exist. They’ve been taken out of that neighborhood.”

Police found at least 11 guns and $70,000 during the raids, said Montgomery Police Chief J. Thomas Manger.

Officials said 17 people from Maryland face federal charges of conspiring to distribute heroin and cocaine. In addition to Gee, officials identified them as Frederick J. Davis, 31, of Gaithersburg; William T. “Fats” Fergerson, 42, of Silver Spring; Tiki Harmon, 42, of Burtonsville; Amir “Meano” Bey-Jones, 41, of Silver Spring; Keenan Jones, 54, of Silver Spring; Jovan Brian “Juvia” Lancaster, 30, who was identified only as being from Maryland; Joseph Miles, 62, of Westerport; Brandon Richardson, 30, of Silver Spring; Alfonso Salazar, 38, also just of Maryland; Ryan Snowden, 30, of Laurel; Sonya Darby “Peaches” Thomas, 37, of Gaithersburg; Rayvon Walls, 25, of Indian Head; Vincent Collins, 36, of Oxon Hill; Sierra Lynch, 37, of Beltsville; Niles, 36, of Bowie; and Abdul Hakim Sauda, 30, of Laurel.

A New Jersey man, Greg Milden, 40, also was charged.