CONAKRY, June 15 (Reuters) - Thousands of girls, some as young as eight, are being kept like slaves in Guinea as unpaid domestic workers who are often beaten or raped by their employers, a human rights group said on Friday. Some of the girls had been trafficked from neighbouring countries in West Africa to Guinea, where there is no child protection system and the abuse of minors is rarely prosecuted, U.S.-based Human Rights Watch said in a 110-page report. "Girls recruited into domestic work in Guinea often live in conditions akin to slavery and many are victims of trafficking," the report's author, Juliane Kippenberg, said in a statement. "The new government urgently needs to take concrete measures to protect girl domestic workers," she said. Nationwide strikes and protests earlier this year against veteran President Lansana Conte's increasingly erratic rule led to the appointment of a new government which has promised to improve living conditions for the former French colony's youth. But it faces a raft of other challenges, not least a mutinous army and a stagnant economy. Child trafficking is a problem across West Africa, with some children forced to work in mines, on the streets or as domestic helpers in countries around the region and others taken to Europe for use in the sex trade. The clandestine nature of the phenomenon makes it hard to measure. But the International Labour Organisation (ILO) estimates that almost a third of the 1.2 million children trafficked each year originate from West and Central Africa. The HRW report quoted one 15-year-old Guinean girl, who was sent by her father when she was eight to work as a domestic help and street-seller in the capital, Conakry. She said the woman she worked for had originally promised her parents she would be sent to school. "When she is gone, her husband wakes me up and rapes me," the girl, who was not named for her safety, told HRW. "He has threatened me with a knife and said I must not tell anyone. He does it each time his wife travels. I am scared."