In a social media post, the FBI said 15 people — identified as “alleged gang members and associates” — were arrested on federal and state charges.

The arrests were made late Wednesday evening by a task force that included the FBI, the Houston Police Department, the Texas Department of Public Safety, the U.S. Marshals Service and the Bureau of Alcohol, Tobacco, Firearms and Explosives.

The names of all the arrested people weren’t immediately available.

However, on Thursday afternoon five people who were among the arrested group appeared in front of a federal magistrate judge, where they were read their rights and appointed defense attorneys.

Four of the men — Darrell Sampson, Kristian Winters, Jacob Barrett and Jocquez Frye — were charged together and accused of conspiring to commit robbery and distribute drugs, according to the charges read aloud in court.

Frye was also charged with with illegal possession of a machine gun.

In a separate case another man, Jordan Strambler, was also charged with illegal possession of a machine gun. 

Officials confirmed after the hearing that the two cases were related. More people were expected to be arraigned in federal court in coming days.

Public records connected to some of the identified men show they live and work in areas of north Harris County.

All of the indictments related to the charges remained sealed as of Thursday afternoon.

Strambler was released on bond following his appearance. Prosecutors are seeking to keep the other four men in custody. A detention hearing was scheduled for next week.

At the hearing, prosecutors could present evidence about the men’s alleged dangerousness or risk of flight.