DES MOINES, Iowa (AP) — Federal agents have arrested the suspected leaders of a Des Moines street gang after a three-year investigation into violent crime and drug dealing.

Court records show a dozen men were arrested Wednesday after the FBI served several search warrants around Des Moines. The suspects are in federal custody, mostly on charges of conspiring to distribute cocaine.

Those arrested include twin brothers Daeron and Marshaun Merrett, whom the FBI calls leaders of the C-Block gang that operates in central Des Moines and is affiliated with the Crips.

The FBI and U.S. Attorney Marc Krickbaum have scheduled a news conference Thursday to discuss what they're calling a "significant" law enforcement action.

Court documents say members of the gang are responsible for shootings, killings, robberies and other crimes. A 75-page FBI affidavit outlines how gang members allegedly obtained cocaine from the Chicago area on a frequent basis to distribute throughout Des Moines.

The document says investigators intercepted phone calls and text messages and used surveillance and informants to penetrate the group.