Authorities struck a blow to Hells Angels motorcycle clubs that traffic in methamphetamines when they arrested 15 people in the Omaha area and one in California, an FBI agent said.

"We're going to knock the socks off the Hells Angels here," said Dennis Aiken, assistant special agent for the FBI in Omaha.Surrounded by confiscated rifles, a .22-caliber automatic pistol, $800,000 worth of drugs, $200,000 in cash as well as Hells Angels jackets and posters, Aiken said a two-year investigation culminated in simultaneous raids Wednesday on 14 locations, including the motorcycle club's headquarters in Omaha.

A Rottweiler guard dog was killed after it attacked an officer at the clubhouse and one man at the clubhouse resisted arrest, but the other searches and arrests were conducted without incident, Aiken said.

"We consider this group to be a major center in the trafficking of methamphetamines," Aiken said at a news conference. Hells Angels clubs have played a major role in methamphetamine traffic in the country, he said.

Many of the fewer than 50 club members in the Omaha area are now in jail, Aiken said. Everyone arrested in the Omaha area Wednesday was a Hells Angel club member or an associate of the club, Aiken said.

The investigation continued and it wasn't known how much contraband and money would eventually be confiscated, Aiken said.

Charges included interstate and foreign travel in support of racketeering enterprises, money laundering, manufacturing and distribution of a controlled substance and felony possession of a firearm, an FBI news release said.

Eleven of the 16 people arrested Wednesday in or near Omaha and in Long Beach, Calif., had been named in a federal grand jury indictment handed up Monday, Aiken said. The five others were arrested on charges of drug possession based on evidence obtained during the raids, he said.

Larry Holmquist, an FBI spokesman, would not comment on the connection between the arrest in California and the others here.

Douglas County Sheriff Dick Roth said the suspects had been investigated as far back as 1978.