Las Vegas police and federal authorities raided eight locations Saturday after a two-year investigation into a prostitution ring with ties to Asia.

The investigation, dubbed Operation Doll House, netted eight arrests and more than two dozen women who probably were forced into prostitution.

Detectives continued to interview the women Monday with the help of interpreters. Most of them spoke little or no English, and most came from Asian countries, said Lt. Dave Logue, who headed the investigation for the Metropolitan Police Department's Criminal Intelligence Section.

Some of the women came from South America, Eastern Europe and the United States. Based on their investigation, police think the women did not enter prostitution on their own.

"Some were brought here by force, and some were tricked into coming here with the promise of a good job," Logue said.

The investigation began about two years ago after a tipster notified police. Neighbors sometimes called in tips during the investigation, but police waited to bust the brothels until they could make cases against the operators, Logue said.

The group advertised with business cards handed out to tourists and through taxi drivers, who brought customers in exchange for kickbacks, he said.

"Once one of these opens up, it doesn't take long for the word to get out," Logue said.

Police raided eight homes and apartments in the area of Arville Street and Spring Mountain Road. They arrested Mouhua Liu, John Gregory Keyes, Xu Yane, Ping Sheng Chang, Yi Feng Ge and Christopher Raven Smith on various charges including living off the earnings of prostitutes.

Smith and Liu were charged with drug trafficking after police found 3,500 Ecstasy tablets and $20,000 during the raids.

Police did not release the names of the other two people arrested.

The prostitutes were taken in by the Salvation Army, which recently received a $450,000 federal grant to help sex trafficking victims.

The women probably were not in Las Vegas for very long as the operation rotated its prostitutes every few months, sending them to another city and replacing them with a new crop of women, Logue said.

The last major human trafficking bust in Las Vegas came in 2000, when federal authorities cracked a similar prostitution ring during Operation Jade Blade.

Five people were arrested on charges they forced women into prostitution after they paid to be smuggled into the United States.

The U.S. Department of Justice recently recognized Las Vegas as one of 17 cities where human trafficking is a concern.

Besides the grant to the Salvation Army, Department of Justice gave a $370,000 grant to the Metropolitan Police Department for anti-trafficking efforts, which includes Miller's position overseeing the Anti-Trafficking League Against Slavery task force. The group includes several local, state and federal authorities.

Las Vegas' sex and construction industries are both ripe for human trafficking, Miller said.

Police know this, and Logue hinted at more busts to come.

"We know this isn't the only organization operating in Las Vegas, and we're not going to let it end here," he said.