Fourteen young Vietnamese women, who were rescued from possible forced work in Phnom Penh brothels, have been arrested for illegal immigration, according to aid workers.

The girls are alleged to have been smuggled into Cambodia to work in the sex trade, but were rescued by human rights activists.

The police say the girls were arrested because they entered the country illegally and would be imprisoned.

But aid agencies say the girls should be treated as victims of trafficking, not as criminals.

It is not clear how old the women are. Aid workers say they are as young as 14, but the police say they are aged 18-20.

The girls were arrested when it was found they did not have correct documentation.

"It's a tragic misunderstanding of justice," Pierre Legros, an advisor to French aid agency Afesip (Acting For Women In Distressing Circumstances) told AFP news agency.

Phuong Sophy, deputy bureau chief of the Ministry of Interior's Juvenile Protection Against Child Exploitation Department, confirmed the girls had been rescued from a brothel after being trafficked into Cambodia.

Cheap labour

News of the girls' arrest came amid warnings that the rise in human trafficking poses a greater international security risk than drugs.

The world's largest regional security group, the Organisation for Security and Cooperation in Europe (OSCE), said criminal organisations were making millions of dollars a year from people-smuggling, despite efforts by law enforcement agencies to stop it.

The OSCE, which is meeting the Asian Regional Forum in Bangkok, said the international community must take urgent measures to crack down on the trade in people.

Millions of men, women and children are bought and sold worldwide every year, the Portuguese ambassador to Thailand told the gathering.

The experts meeting in Bangkok have argued that not only do the people being smuggled risk their lives en-route to unknown destinations, but are likely to end up as prostitutes or cheap labour in sweat shops throughout Europe, the United States and Asia.

Our correspondent in Bangkok says that although the conference is unlikely to come up with solutions, its organisers hope it may be able to suggest concrete formulas or strategies for combating the trade.

The Thai Government, which is co-hosting the meeting, has offered to sponsor OSCE training courses, in which their Asian regional security partners could participate.

Earlier this month, the US State Department estimated that more than four million people were bought and sold into the slave trade last year.