A growing number of adolescent girls from eastern Europe are being sold into sex slavery in the west, charitable organisations told an international conference on child trafficking in Rome yesterday.

Every year more than 6,000 children aged between 12 and 16 are smuggled into western Europe to work as prostitutes and drug traffickers or to beg, the children's charity Terre des Hommes said.

Around 2 million juveniles worldwide fall victim to people-smugglers every year, it said.

Researchers have identified north-eastern Italy as a key sorting centre for girls from eastern Europe who are either sold by their parents, kidnapped by organised crime gangs, or lured abroad by the mirage of a better life.

There is a particularly high concentration of juvenile sex slaves in the area between Padua and Venice, with 20% of prostitutes under the age of 18, compared to 5% in other Italian cities, the charity said.

Last year 250 girls managed to escape from their exploiters and seek assistance from the Italian state.

Those falling victim to people-traffickers are becoming younger, and the crime gangs are adopting increasingly sophisticated techniques to prevent them from coming to the attention of the police, said Barbara Limanowska, the author of a Unicef report on the trafficking of women and children in south-eastern Europe.

Some 10-30% of all eastern European sex workers are minors, Ms Limanowska said. Save the Children estimates that up to 80% of people trafficked from Albania are teenage girls under 18.

Italy is the people-smugglers' gateway to western Europe, Ms Limanowska said, while Turkey is now the staging post for women on their way to the Middle East.

"The women are kept in apartments and places where police access is not easy, and then work in bars, clubs and brothels rather than on the streets," she said.

"The gangs use mobile phones to organise their activity and move the girls from place to place to avoid discovery."

Ms Limanowska said Albanian gangs, notorious for their ferocity, were taking control of the prostitution business throughout Europe.

Ms Limanowska said there was strong demand for the services of teenage prostitutes, and no evidence that western clients were affected by either moral scruples or fear of breaking the law.

"It's not only the traffickers and the clients that don't care that the women are under age, but the assisting agencies as well," she said. "That has got to change."

For the pimps, "ownership" of an under-18 prostitute can be a source of pride, according to another report. The risks and rewards involved confer a form of prestige on the underworld bosses.

Ms Limanowska said it was time that greater emphasis was put on the human rights of the victims, rather than focusing attention on the phenomenon as a security or migration issue.

"The Italian model is exceptional in Europe. It's more humane, but also more productive. There is better assistance to the victims, but also a lot of work done on the prosecution of traffickers. That is important for the safety of the women," said Ms Limanowska.

"It's vital that they stay and testify against their exploiters rather than simply being sent back to their country of origin."

She said that Britain had been slow to recognise the sexual exploitation of minors.

"There are cases in Britain of women from Kosovo, Bosnia-Herzegovina and Romania - but there is not much information about what is really going on. They have only woken up to the problem recently."