LONDON (AP) - Seven men in Britain were given long jail sentences on Thursday for sexually exploiting girls as young as 11 who were given alcohol and drugs before being trafficked for sex.

The men were convicted last month at London's Central Criminal Court of charges including rape, trafficking and child prostitution.

Prosecutors said the men were part of a paedophile sex ring that exploited girls between 2004 and 2012 in the Oxford area, 95km north-west of London.

Judge Peter Rook imposed sentences ranging from seven years to a minimum of 20 years. He told the ringleaders, brothers Akhtar Dogar and Anjum Dogar, they were guilty of "exceptionally grave crimes".

He said the gang picked on girls who were "vulnerable, underage and out of control".

"You would build up their trust and provide them with drink, drugs and the attention which they craved," he said.

The girls were taken to various parts of Britain and forced to have sex with men for money.

The case follows several other high-profile prosecutions of sex rings that preyed on underage girls, many of whom were in state care.

The crimes have raised racial sensitivities, since the perpetrators in several cases have primarily been South Asian men, while many of the victims were white.

Children's advocates and victims' rights groups say the main issue is authorities' failure to protect vulnerable children, and to listen to them when they report abuse.

Six victims testified at the trial of the Oxford ring, with one recounting how she was threatened with arrest for wasting police time when she complained of abuse.

Mr Peter Wanless, chief executive of the National Society for the Prevention of Cruelty to Children, said the case showed the need for "a fundamental shift in how the system treats vulnerable young people".