LONDON >> Britain is wrestling with a volatile nexus of crime, race and religion, after 18 people were convicted of sexually abusing women and girls as young as 15.

One woman and 17 men were convicted of, or admitted, to charges including rape, supplying drugs and inciting prostitution in a series of trials that ended this week at Newcastle Crown Court in northeast England.

The crimes follow a pattern that has become grimly familiar from cases across Britain in the last few years. The convicted men mostly come from South Asian Muslim backgrounds. Their victims — who were plied with drugs and alcohol before being abused at parties, in taxis or in back rooms — are mostly white.

The prosecution of child-grooming gangs in Rochdale, Rotherham, Oxford and now Newcastle has raised uncomfortable questions. Some allege that the crimes were long ignored by authorities afraid they would be branded racist or fearful the allegations might inflame ethnic tensions.

Sarah Champion, a British lawmaker from Rochdale, said today that the causes of abuse weren’t being tackled “because people are more afraid to be called a racist than they are afraid to be wrong about calling out child abuse.”

Ken Macdonald, Britain’s former chief prosecutor, said some of the blame lay with particular communities who regarded “vulnerable and disordered young girls (as) just opportunities for sexual abuse.”

“It is a disease of racism and sexism that will not abate until it is confronted culturally in homes, schools and places of worship as a question of dignity, respect and equal rights,” he said.

The recent high-profile cases aren’t typical of all child sexual abuse. Most abused children are victimized online, at home or in institutions such as schools, and most of the perpetrators are white men. Police say that in the year to October 2015, 12 percent of offenders in child sexual exploitation cases were from South Asian backgrounds, and 59 percent were white.

But former prosecutor Nazir Afzal, who brought the Rochdale abuse gang to trial, says Pakistani men are disproportionately involved in the sort of “street grooming” seen in Newcastle.

He says factors may include sexist attitudes to women and other “cultural baggage,” and the large number of South Asian men working in the nocturnal economy.

“These young girls are invariably looking for warmth, for transport, for food, for mind-numbing substances,” he said. “The predators are hiding among the takeaway workers and taxi drivers.”

Some experts say the focus on South Asian perpetrators masks how widespread child sexual abuse is, and overlooks the fact that victims are often ignored by authorities because of their youth and troubled backgrounds.

Helen Beckett, an expert on child sexual exploitation from the University of Bedfordshire, said focusing on one ethnic group risked missing other patterns of abuse.

“The emphasis that we’ve had on (abuse) being perpetrated by Asian males means that that is often what we are looking for, and therefore are more likely to find,” she said.

“We know child sexual exploitation takes so many different forms. “

Since the Rochdale case shocked the nation in 2012, police and lawyers have worked hard to prosecute grooming gangs — though some police tactics have drawn criticism. A child welfare group expressed alarm at a police decision in Newcastle to pay a convicted child rapist to act as an informant.

Steve Ashman, head of the Northumbria Police force, acknowledged that paying a convicted pedophile “may appear repugnant,” but said his information had been crucial to convicting the gang.

He said police had “thrown the kitchen sink” at the crime of child sex abuse, deploying 50 officers for more than three years in an operation that has netted 93 convictions, including the ones this week.

Afzal said there had been progress, but that much more needs to be done.

“You turn over a stone and you will find this kind of behavior pretty much everywhere in this country,” he said. “The demography might change but the behavior remains the same. Where there are available and vulnerable young girls, and boys, there are predators.

“There is no community where women and girls are safe. None.”