By Yereth Rosen

ANCHORAGE, Alaska (Reuters) - Jury selection began on Monday in the conspiracy trial of three Alaska militia members accused of plotting to kill state and federal law enforcement officers and amassing an arsenal of weapons to carry out their plans.

Alaska Peacemakers Militia leader Francis Schaeffer Cox, 28, and associates Lonnie Vernon and Coleman Barney are charged in U.S. District Court in Anchorage with conspiracy to commit murder and federal weapons offenses.

They were arrested in March 2011 after authorities said they had collected an arsenal of illegal weapons - including grenades and machine guns - and were hatching a plan to kill Alaska state troopers and federal law enforcement agents.

The case has drawn considerable attention in Alaska. Of 88 prospective jurors assembled at the start of Monday's proceedings, at least half raised their hands when asked by U.S. District Court Judge Robert Bryan if they had heard or read news reports about it.

Nine potential jurors were excused after admitting they already had strong opinions about the case.

Cox had been a fixture in the Fairbanks political scene who ran unsuccessfully in the 2008 Republican primary for a state House seat.

The trial is being held in Anchorage over the defendants' objections. They filed an unsuccessful motion last September seeking to move the case to Fairbanks.

Cox is also affiliated with the "sovereign citizens" movement, whose members claim they are their own sovereign entities and are not subject to U.S. or state laws.

A judge from Tacoma, Washington, is presiding over the trial because Lonnie Vernon is accused in a separate case of plotting to kill an Alaska-based federal judge.

Vernon and his wife, Karen, are charged with conspiring to kill U.S. District Court Judge Ralph Beistline and members of the judge's family. Prosecutors said the Vernons were upset about Beistline's rulings in a federal income tax case, court documents showed. That trial is due to start in September.

(Editing by Dan Whitcomb and Cynthia Johnston. Desking by Christopher Wilson)