(CNN) -- A string of "brazen attempts" to kill members of a gang task force in Riverside, California, has led to a $200,000 reward for information.

Authorities hope the reward will encourage people to come forward with information related to three booby traps targeting members of the Hemet Gang Task Force, part of a countywide initiative dedicated to combating gang-related violence in Riverside.

"These brazen attempts to kill police officers in the line of duty are an outrage and even a form of urban terrorism. Our brave men and women in uniform put their lives on the line every day to keep our streets safe," California Attorney General Jerry Brown said Thursday. "We urge anyone with information on the attacks to come forward immediately."

Brown was joined by Riverside District Attorney Rod Pacheco, Sheriff Stanley Sniff, Hemet Police Chief Richard Dana and Riverside County Supervisor Jeff Stone in the public appeal for information.

Multiple local, state and federal agencies, including the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives contributed to the reward.

Authorities believe the close timing and identical targets of the attacks indicate they could be related, said John Hall, a spokesman for the district attorney's office.

On December 31, 2009, the unmarked headquarters of the Hemet Gang Task Force was targeted by someone who redirected the natural gas line on the roof into the building, filling up the office with deadly gas. Two task force members entering the office smelled gas and backed away before flipping the light switch and potentially causing the building to explode.

On February 23, a task force member at the Hemet headquarters opened a security gate outside the building, which launched a homemade zip gun attached to the gate. The weapon fired, missing the officer's head by inches.

The headquarters has since been moved to an undisclosed location, where extra security precautions are being taken, Hall said.

On March 5, 2010, criminals targeted a task force member who had parked an unmarked police car in front of a convenience store in Hemet. The officer found what appeared to be a homemade pipe bomb hidden underneath the vehicle.

"There's a person or people out there, a bunch of idiots that are trying to do damage to us. We mean to catch them. We mean to see them spend the rest of their life in jail," Dana said. "I'm hoping now, with $200,000, somebody's gonna have noticed one of them, call us, tell us who it is, and let us get something done."

Hemet is one of eight local, state and federal agencies that make up the Riverside County Gang Task Force, which was formed in 2006 to address the growth of criminal street gangs and outlaw motorcycle gangs countywide.

As the county expanded and its population grew, so did the presence and reach of organized crime, Hall said. Since 1997, the number of gangs in Riverside County has grown from 266 to 391, according to the task force's Web site, and total gang membership has grown to 10,620 members countywide.

Since the task force's inception, the number of gang members and violent crimes has decreased and the amount of arrests and warrants served has increased, Hall said.

On Wednesday, at least 31 members of the Vagos motorcycle gang were arrested at locations throughout Riverside County in "Operation Everywhere," which spanned four states.

Hall said he could not say whether the Vagos were believed to be involved in the Hemet booby traps, citing an ongoing investigation. He said it was safe to assume that some gang activity was involved in the attacks.

"It's possible that the gang members are feeling threatened, that we're starting to impede on their activity and they're retaliating," he said. "The investigation is still fluid and no arrests have been made, but they're not targeting regular police. It's reasonable to believe that they are targeting members of the task force specifically."

CNN's Brett Roegiers contributed to this report.