The United Nations Human Rights chief has said there is a sharp increase in attacks on albinos in Malawi and neighboring Tanzania.

The U.N. said earlier this week that six incidents were reported in Malawi since the beginning of 2015, compared to only four in the previous two years. The Association of Persons with Albinism in Malawi on Wednesday said it has recorded 11 attacks since December 2014.

The U.N. said Tanzania recorded eight attacks since August last year.

High Commissioner for Human Rights Zeid Ra'ad Al Hussein in a statement described the attacks as "vicious." The murders stem from superstitious beliefs that albino body parts bring wealth and luck.

Albinism is a genetic condition by which people are born with little or no pigment in their skin and eyes.