Law enforcement officials arrested 40 people and seized drugs, cash and weapons, seriously denting Omaha operations of a street gang with ties to Central America, officials with several agencies said Tuesday.

The arrests were part of an ongoing investigation of the gang Mara Salvatrucha, or MS-13.

Fifteen of those arrested were linked directly to the gang and charged with various gun, drug and immigration violations, First Assistant U.S. Attorney William Mickle said. Ten were charged federally and five faced state charges.

While searching for gang members, authorities arrested 25 people and charged them only with being in the United States illegally, said Bill Wallrapp, resident agent-in-charge of U.S. Immigration and Customs Enforcement.

Wallrapp said authorities were still determining whether some of those people were tied to the gang.

Authorities seized illegal weapons, 20 pounds of marijuana, a half pound of methamphetamines and 4 ounces of cocaine, Omaha Police Chief Thomas Warren said.

Agents with the FBI, ICE, the Drug Enforcement Administration, the Nebraska State Patrol and Omaha and Bellevue police continued executing search warrants and making arrests Tuesday, and authorities expected gang arrests and indictments to rise.

"We're on our way to dismantling MS-13 here in Omaha," FBI Special Agent-in-Charge John Kavanaugh said.

Details about the charges and those suspected were not immediately available because the indictments were sealed.

The arrests came as part of Operation Community Shield, a national initiative targeting gangs that was launched more than two years ago after federal officials identified the MS-13 gang as one of the nation's largest and most violent.