LONDON (AP) — Seven men were convicted Monday of sexually abusing vulnerable teenagers in a prosecution sparked by revelations of sexual exploitation stretching back years in a northern England town.

A 2014 report said that more than 1,400 young people were victims of sexual exploitation in Rotherham between 1997 and 2013.

In a pattern repeated in several other U.K. towns and cities, the perpetrators were mostly men of Pakistani heritage, who befriended teenage girls and plied them with gifts, alcohol and drugs before abusing them.

Prosecutor Michelle Colborne said the victims, now in their 30s, were "targeted, sexualized and, in some instances, subjected to acts of a degrading and violent nature at the hands of these men who sit in the dock."

"None of them had the maturity to understand that they were being groomed and exploited," she said.

A jury at Sheffield Crown Court convicted seven defendants of charges including rape and indecent assault. They will be sentenced Nov. 16. An eighth defendant was acquitted.

The cases in Rotherham, Huddersfield, Rochdale and other towns — in which most of the victims were white — have heightened ethnic tensions in Britain. They also have spurred criticism of local authorities, who failed to protect vulnerable girls, and of police, who often didn't listen to victims they regarded as troublesome teenagers.