Nine women from Ciudad Juarez, a border city in northern Mexico, were rescued by municipal police officers from a shelter for victims of violence, where they were being forced to work as prostitutes, a police spokesman said.

The women told investigators that the shelter operated as a "date house," where men were invited by the organization's director to meet women, police spokesman Adrian Sanchez said.

Several children living at the shelter were also forced to engage in prostitution, the women said.

Mujeres Unidas contra la Violencia shelter director Soledad Griensen, 53, was arrested and turned over to prosecutors, Sanchez told Efe.

Local officials have expressed concern about the high level of people trafficking in Ciudad Juarez, considered Mexico's murder capital and the most dangerous city in the world.

Ciudad Juarez, located across the Rio Grande from El Paso, Texas, first gained notoriety in the early 1990s, when young women began to disappear in the area.

More than 500 women have been killed in Ciudad Juarez since 1993, according to the National Human Rights Commission, with the majority of the cases going unsolved.

In most of the slayings, the victims were young women from poor families who moved to the border city from all over Mexico to work in the many assembly plants, known as "maquiladoras," built there to take advantage of the North American Free Trade Agreement.

Investigators have not determined who is behind the killings, although there has been speculation that serial killers, organized crime, people traffickers, drug smugglers and child pornographers, among others, may be involved.

"Juarez Competitiva," a conference designed to find ways to improve the border city's image, started on Oct. 13 and runs until the end of the month.

The conference, which includes cultural events, is being held in an effort to restore the tarnished image of Ciudad Juarez, where about 9,000 people have died in drug-related violence in the past four years.

The series of events will feature a number of prominent speakers, including former New York Mayor Rudy Giuliani and Mexican astronaut Rodolfo Neri Vela.