Twenty men have been jailed for raping and abusing more than a dozen girls in a northern England town, in what a judge called a “vile and wicked” campaign of exploitation.

The men in the town of Huddersfield were found guilty in three trials this year, but the verdicts could not be reported until a judge lifted reporting restrictions on Friday.

The cases are the latest in a series of prosecutions in northern English towns and cities for child sexual exploitation involving British Asian men of mostly Pakistani heritage.

The men were accused of being part of a gang that groomed vulnerable girls described in court as from “isolated” backgrounds and were convicted of more than 120 offences against 15 victims aged between 11 and 17.

Prosecutors said the victims were plied with alcohol and drugs before being sexually abused by the men at parties and in cars, parking lots, a snooker centre and a fast-food restaurant.

Amere Singh Dhaliwal, whom prosecutors said was the gang’s ringleader, was found guilty of 22 counts of rape and sentenced earlier this year to a minimum of 18 years in prison. The judge told him that “the way you treated these girls defies understanding.”

“This abuse was vile and wicked,” judge Geoffrey Marson said as he passed sentence at Leeds Crown Court.

The other men received sentences of between five and 18 years in prison.

The cases in Huddersfield, Rochdale and other towns in which most of the victims were white have heightened ethnic tensions in Britain and spurred criticism of local authorities, who failed to protect vulnerable girls, and of police, who often did not listen to the victims.

Far-right figures have used the crimes to argue that “Muslim grooming gangs” pose a particular threat to Britain.

Anti-Muslim activist Stephen Yaxley-Lennon, who uses the pseudonym Tommy Robinson, was jailed for contempt of court in May after broadcasting live on Facebook outside the trial of some of the Huddersfield gang, breaching reporting restrictions.

Police statistics in Britain show that most offenders in child exploitation cases are white men, and most of the abuse takes place online, at home or in institutions such as schools.

But former prosecutor Nazir Afzal, who has brought many abusers to trial, says Pakistani men are disproportionately involved in the sort of street grooming seen in recent high-profile cases.

He says that reflects the high number of South Asian men working for taxi firms and takeaway restaurants in the late-night economy, as well as their widespread sexist attitudes about women.