Tanzania has banned witch doctors in a bid to curb a rising wave of attacks and murders of albinos whose body parts are prized for witchcraft after a four-year-old albino girl was kidnapped from her home by an armed gang.

More than 70 albinos, who lack pigment in their skin, hair and eyes, have been murdered in the east African nation in the past decade for black magic purposes, according to United Nations figures, many hacked to death and body parts removed.

The government has accused witch doctors of fuelling these killings by luring people to bring albino body parts which they grind up with herbs, roots and sea water to make charms and spells that they claim bring good luck and wealth.

The nationwide ban come less than a week after UN officials urged the government to step up efforts to end the discrimination and attacks after a girl was abducted last month from her home in northern Mwanza region. She is still missing.

Tanzania's Home Affairs Minister Mathias Chikawe said the government has formed a national task force involving the police and members of the Tanzania Albino Society to arrest and prosecute witch doctors defying the ban.

"We have identified that witch doctors are the ones who ask people to bring albino body parts to create magical charms which they claim can get them rich. We will leave no stone unturned until we end these evil acts," Chikawe told reporters.

Chikawe said the operation would begin in two weeks time, initially targeting five regions, including Mwanza, Tabora, Shinyanga, Simiyu and Geita, where the government believes attacks against albinos are most prevalent. The operation would be expanded to other areas later.

He said the task force will also have the mandate to review previous court cases of albino attacks and killings to gather new evidence and further research the motive for attacks. The Director of Public Prosecution would prioritize these cases.

The government has previously been widely criticized for failing to act to stop these macabre murders.

The Tanzania Albino Society welcomed the move, saying it would help end the worsening plight of albinos.

"I believe we can work together to end these acts of pure evil," said spokesman Ernest Kimaya, a sufferer of the pigment disorder.

But Rashid Mauwa, a traditional healer from the Bunju area of Dar es Salaam, said he feared the ban would lead to victimization of healers of whom only a few engage in witchcraft.

"I am not engaging in any witchcraft. I am only using traditional herbs to help people who do not respond to conventional medicines. Why am I being punished?" he told the Thomson Reuters Foundation.

Albinism is a congenital disorder which affects about one in 20,000 people worldwide, according to medical authorities. It is, however, more common in sub-Saharan Africa, affecting an estimated one Tanzanian in 1,400.