The government of Haiti is being urged to take action to stop the wave of sexual violence that is blighting the lives of young women in one of the world's poorest nations.

An online petition has been launched by Amnesty International to protest at Haiti's high incidence of rape, often of young girls by gangs of armed men, that was first highlighted in 2006 when UN workers discovered that up to half of the women living in the capital Port-au-Prince's vast slums had been the victims of rape.

Since then the government, which only made rape a crime in 2005, has taken little or no action to hunt down the offenders, among whom are said to be police officers.

Filmmaker Xanthe Hinchey met several victims forced into hiding after their attacks because of the risk of being killed. Nahomey, now 21, told how she was raped in the street: "It was a policeman and a civilian. Now they say they will kill me because they are in prison."

Another girl, 17-year-old Jina, is now pregnant after being raped by three men.