Thousands of people in Tanzania have been taking part in an exercise aimed at identifying those behind the killing of albinos for ritual purposes.
The process - in which people fill in forms anonymously, naming those they suspect of involvement - was ordered by President Jakaya Kikwete.
But some fear the nationwide exercise, which has begun in the Lake Zone area, could be used for personal vendettas.
Witchdoctors reportedly buy albino body parts to make "magic" potions.
Since late 2007, 45 albinos have been slaughtered in Tanzania.
Forty-four of the killings have taken place in the Lake Zone district.
Police believe the killers are selling their victims' limbs, hair, skin and genitals to traditional medicine practitioners who make potions promising to make people wealthy.
Superstitious miners and fishermen in the region hoping to get rich quick have been accused of fuelling the demand.
President Kikwete has said the murders have brought shame on the country and urged the public not to fear retribution for naming the culprits.
But correspondents say it is not clear how effective the exercise will be in a society which believes in witchcraft and where confidence in the legal system is wearing thin.
UN Secretary General Ban Ki-moon last month decried the albino killings during his official visit to the country.
The government issued a ban on all traditional healers in January in an effort to stop the killings and several have been arrested since then on suspicion of flouting the order.