Domestic workers or modern day slaves?

Tonia Ayo-Ola, 19, has worked for three months without a day off. Each morning she is up by 6 a.m. preparing breakfast for her "master".

She doesn't roll out her sleeping mat on the living room floor, until after the last person is in bed, often well after midnight.

"I have no friends, I never go out and no one comes looking for me. I am not happy. It is not that they are wicked to me but it is not like being with my family - I am not free," Tonia said.

Tonia has never been paid for her toil, though she knows the traffickers promised her family an unspecified sum of money at the end of the year, when she hopes to return home.

If the girls get any money at all after the traffickers have levied their "transport fees" and "commission" it is only a fraction of what they laboured for, said Justina Onifade of the United Nations Chidlren's Agency, UNICEF.

Across West Africa, millions of girls like Tonia -- and less often boys -- are effectively sold into slavery as domestic workers. Sexual, physical and emotional abuse is widespread. Many are kept under lock and key, and have no contact with anyone outside their employers - no one to turn to for help.

Once away from their families, the girls are at the mercy of the traffickers who, in some cases, move them from household to household pocketing their wages.

Tonia Ayo-Ola's ordeal started when recruiters came to her village in Ogun State just north of Lagos and said they could fix her up with a job as a domestic worker with a well off family in the city.

A deal was struck with her brother, and the next thing Tonia knew she was heading to Lagos to work in a stranger's house.

As the largest city in sub-Saharan Africa, Lagos is a nerve centre for human trafficking according to UNICEF.

Tackling Nigeria's problem with internal trafficking is a first step towards addressing Nigeria's role as a hub for international human trafficking networks, according to Orakwue Arinze of the Nigerian government's National Agency for Prohibition of Traffic in Persons (NAPTIP).

"Internal trafficking is the ingredient for international trafficking as once [these girls] are taken from their family, anything can happen," Arinze said.

Child trafficking is one of the fastest growing organised crimes with an estimated 1.2 million victims per year, according to UNICEF.

In a regional bid to tackle the problem, members of the regional economic body ECOWAS recently agreed on a plan of cross-border cooperation.

In an additional measure, the Nigerian government has passed a law making it illegal for under 18s to work in the household of non-family members. But labour is so cheap that domestic help is the norm, and few Nigerians are aware of the law.

NAPTIP officials say that it's a fight against poverty in a country where the UN estimates 70 percent of the population live on less than US $1 a day.

"Poverty can make someone act like an animal, as it is animalistic to look at your children like something you can sell - in fact, even animals don't do that," NAPTIP's Arinze said.

NAPTIP is working with UNICEF to reunite trafficked domestic workers with their families. But UNICEF's Onifade said the task is complicated because some of the youngest children do not know their father's names or where they are from.

For others, UNICEF is working with the government to provide hundreds of domestic workers in Lagos with vocational or literacy classes to broaden their horizons.

At the Agege Vocational Training Centre, young women, girls and one or two young men, can chose from a range of classes, including hairdressing, fashion design and even "snailery", the rearing of African giant snails which are a favourite dish in southern Nigeria.

Just getting the girls out of the house and around other people can dramatically improve their situation, enabling them to meet peers and perhaps find support if they feel they are being abused or mistreated.

But the free programme will probably never reach the most vulnerable girls.

"At these centres girls are brought out of the house. They get to know their rights, they share experiences and get support," Onifade said. "That is exactly the reason some masters will never release them."