Federal authorities have charged 27 people involved in what they say is a large-scale drug ring that operated out of an abandoned house in Newark and brought in as much as $13,000 in one day.

According to the U.S. attorney's office Tuesday, 20 people have been arrested.

Five others were in custody already, while two remain at large.

The ring allegedly was connected to the Bloods street gang and sold heroin and crack cocaine within blocks of an elementary school.

"The organization made efforts to fortify the abandoned house by boarding up all the windows, using an old defense style to make sure no one could get in on the first floor,” says U.S. Attorney Craig Carpenito. “They had to go to the second floor to enter."

A criminal complaint alleges the group took over an abandoned house and sold drugs through a hole in a floor to customers who would climb a ladder to a second story.

The group also allegedly used other nearby properties to sell drugs.

Authorities began investigating the group in 2017.