Two Salt Lake City men face federal sex trafficking charges for allegedly using death threats and physical confinement to force two women to work as prostitutes.

The indictment, announced Wednesday, elevates charges already filed in 3rd District Court against the men, 21 and 26. Those earlier charges allege that in September and October 2008, the 26-year-old ordered a woman to perform sex acts in exchange for money and took 50 percent of the take. When the woman said she did not want to perform sex acts, he told her she had no choice, police wrote.

Over time, the man took a greater portion of the revenue by having his driver, the 21-year-old, wait for the woman after her "dates" and take her money, the charges state. When the woman resisted, he assaulted her, verbally abused her and threatened to kill her, police wrote.

The woman phoned a friend to plan an escape, but the man was there when she arrived at the meeting place, police wrote. He "yanked her out of her car by the hair and told her that if she tried to stop working for him, he would cut her up," police wrote.

In another incident, the 21-year-old showed a gun to her and said he would shoot her if given orders by the 26-year-old, charges state.

Police located the victim in a sting in which she agreed to have sex with an undercover officer for $600, police wrote.

In a separate case, the same 26-year-old is accused of forcing a second woman to work as an escort, advertising on Craigslist, in June and August 2008.

Both men face two counts each of sex trafficking in U.S. District Court.