Mexican prosecutors have arrested 12 people in connection with the slayings of 11 young women whose skeletal remains were found near the northern border city of Ciudad Juarez early last year.

The suspects include alleged drug dealers, pimps and small store owners. They allegedly belonged to a gang that forced young women into prostitution and drug dealing and then killed them when they were "no longer of use," the prosecutors' office for the northern state of Chihuahua said in a statement late Tuesday.

The 10 men and two women face charges of human trafficking and homicide. Six were already in local jails for other offenses, and six other were detained early Tuesday.

Ciudad Juarez, across the border from El Paso, Texas, was the scene of a series of killings of more than 100 women beginning in 1993. Those possible serial or copy-cat killings, with similar victim profiles and killing methods, appeared to taper off by late 2004 or early 2005. In those cases, the victims were usually young, slender women, often factory workers, who were abducted, often sexually abused and strangled before their bodies were dumped in the desert.

Few of those cases were ever properly investigated, but activists and mothers of the latest victims said Wednesday that they had pressured investigators and provided information that led to the suspects.

One of the suspects ran a modeling agency, another a clothing store, a third a small grocery.

"These businesses were used by the gang as a `hook' to offer young women jobs. Once they obtained the information they needed from the women's job applications, they used different techniques and other people to kidnap them or pressure them into forced prostitution, and the consumption and or sale of drugs," the state attorney general's office said.

"Once the women were no longer useful for their illegal activities, they decided to kill them and abandon their bodies" in the Juarez Valley, just east of Ciudad Juarez, it said.

Maria Garcia Reynosa, the mother of Jessica Leticia Pena Garcia, who was 15 when she disappeared in 2010, said she obtained video showing her daughter entering one of the suspects' businesses, a boot shop, looking for work.

Garcia Reynosa said that she had to do much of the investigative work herself, but that prosecutors finally listened to her and followed up the leads she provided on a hotel where she believed her daughter had been held. Unfortunately, it was too late by then; Jessica Leticia had been killed months earlier.

"I gave them everything on a silver platter, and these dogs didn't do anything," she said of the original investigators. She said she had to battle to get key evidence introduced, and deal with detectives who didn't take her leads seriously.

"I'm in this for all of us," she said of the victims' mothers. "I feel that she (Jessica) is with me, helping me."

Finally this year, the state created a small team of investigators devoted to focusing on the murders.

The difference from the earlier cases is that victims in Mexico are now much more empowered than in the 1990s, and prosecutors are more willing to listen. Moreover, with more than 24,000 people reported missing over the last six years in Mexico, a strong tradition has emerged of relatives taking it on themselves to carry out basic investigation tasks that police can't or won't do.

"This was done with the creation of the investigative agency, our presence and the efforts of the mothers, who were the ones who provided leads from the beginning," said Norma Ledesma, leader of the advocacy group Justice for Our Daughters. "They (the mothers) carried out their own investigation."

"Mothers today know their rights," Ledesma said.

A dozen sets of bones were found in January and February 2012 in fields in the Juarez Valley, a largely agricultural area. Little but bones were found, and the remains were in such bad condition that experts had trouble  establishing ages, identities, causes of death and number of victims. But among those identified, there was a similarity in ages: two were 15, one was 16, two were 17 and one 19.

According to prosecutors, after recruiting the women "with lies or threats," or abducting them between 2009 and 2010, the suspects held them in forced servitude at a local hotel. There, an adult prostitute, one of those arrested, would keep an eye on them, bring them customers and report any escape attempts to another gang member who was in charge of punishing the captives.

Some were forced to sell drugs, and killed if they didn't turn in enough money.

While Ledesma expressed satisfaction with the charges brought in the recent killings, she said it can't end there.

"We are not going to be convinced that it was just this small gang that was taking them away. There are higher-ups involved," Ledesma said. "We are not going to be content with the capture of just the underlings if the leaders are still free."

Malu Garcia Andrade, who heads the activist group Nuestras Hijas de Regreso a Casa, said she believes many of an estimate 80 other women who have gone missing in Ciudad Juarez in recent years may have fallen victim to the same or similar trafficking gangs.

"We have a lot of cases of girls who disappeared in Ciudad Juarez, whose profile is the same, whose appearance is the same," said Garcia Andrade, who brought a half-dozen victims' relatives to Mexico City to demand action Wednesday. "The all had gone out to apply for jobs and then they disappeared."

Ciudad Juarez has long been a manufacturing hub, drawing workers from other parts of Mexico to its assembly plants. But the years from 2008 to 2011 were marked by an upsurge in drug cartel violence and an economic downturn in the area.

Garcia Andrade is convinced that drug cartels allowed, or had a hand in, the women's disappearances and killings.

"The organized crime gangs from Juarez operate in the Juarez Valley," she said, "and nobody is dumping bodies in the Juarez Valley without their knowledge."