An armed gang kidnapped, killed and dismembered an albino girl in what was Burundi's 18th such slaying in less than four years, officials said Sunday.

People with albinism, a genetic condition that limits or prevents entirely the production of body pigment, have long been the target of discrimination in several African countries.

Beliefs attributing albinos special powers exist in the region and the victims' limbs are sometimes sold to witchdoctors.

In the latest attack overnight Saturday, seven men armed with spears, a rifle and machetes went into a home near the capital Bujumbura and kidnapped a 15-year-old girl, local official Leonce Ndirinzirindi said.

The group then killed her and chopped off her arms and legs, which they took with them, he added.

Eighteen albinos have been killed since August 2008. The rate of killings dropped off after August 2009, when eight people were convicted of the murder and attempted murder of albinos.

Kassim Kazungu, the president of group Albinos Sans Frontieres, said the government was failing to protect albinos and said everyone sentenced to prison in the killings had escaped.