By Will Ross BBC West Africa correspondent

The report by Human Rights Watch says many girls are forced to work up to 18 hours a day for no pay and are physically abused by employers.

The girls often live in conditions akin to slavery and many are victims of people trafficking, it says.

Human Rights Watch says the problem is not specific to Guinea and little is being done to solve it.

Deprived of education

The research in Guinea showed that thousands of girls spent their childhood and adolescence doing housework, such as cleaning, washing and taking care of small children, often for no pay.

In pictures: Guinea maid

The report said the girls were vulnerable to sexual abuse and many were beaten with whips, electric cords and sticks.

They are often trapped in this cycle of abuse partly because they are deprived of an education.

The widespread poverty across the region makes child labour an all too common phenomenon, the report says.

Human Rights Watch says most of the employers in Guinea are women from the urban middle class who demand a girl from poorer relatives or from an intermediary in the countryside.

It says ending abuses against these girls should be a priority for the government.