Two men in the US State of Pennsylvania have been charged in a "horrible" case of human trafficking after allegedly using drugs and violence to force six women into prostitution. Kenneth Crowell, 34, and Barry "Bear" Schiff, 50 face multiple charges, including trafficking, involuntary servitude, drug possession and prostitution.

Police said that the prostitution ring operated by the duo was busted following a sting where undercover state troopers responded to a prostitution ad on the website Backpage. The ad reportedly had a number linked to nearly 350 similar adverts, according to a Pennlive report.

Pennsylvania's attorney general, Josh Shapiro, said on Tuesday (28 November) that the two accused gave death threats and opioids to force the victims to work in the prostitution ring.

"This is a horrible case where women were lured into prostitution by the false premise of easy money," he said. "When the victims tried to leave, these criminals used violence and threats of violence to keep them working as prostitutes against their will."

The ring was said to be active from 2014 until October this year in Lancaster, Montgomery, Philadelphia and York counties and southern New Jersey

Shapiro said that Schiff was already in the York County Prison when the human trafficking charges were filed against him, while Crowell was arrested near Chicago over the weekend.

According to Shapiro's office, both men are in custody, and online court records did not list defense lawyers for them.

A grand jury report detailed the harrowing methods used by the two men to control the women. One victim told police that she was recruited from a York County strip club, but she wanted to escape his clutches.

In one incident, Schiff had allegedly slammed a woman's head into a bucket containing bleach and shards of broken glass after she refused to have sex with him, leaving her with permanent scars and injuries. In another incident, Schiff allegedly told a victim he would "chop her up into little pieces and throw her in the river" if she tried to leave the ring.

The arrest of these two men reportedly marked the second human trafficking case brought by the state attorney general's office and Pennsylvania State Police in recent weeks.

Earlier in November, two defendants stood trial on human trafficking charges in Montgomery County. That case was uncovered with the help of an Uber driver who alerted police of a trafficking victim, Fox29 news reported.