Vistors to the the week-long fair in Dar es Salaam will see a rather gruesome exhibit of human body parts in an effort to raise awareness about the underground trade in human skin which has hit southern Tanzania over the past two years.

The head of the forensic science division in the chief chemist's office, which is exhibiting the parts, Gloria Machube, told the BBC's Focus on Africa programme that the human skin is used in witchcraft.

According to police the skins are in huge demand outside Tanzania.

They are transported to Malawi, Zambia, Mozambique, South Africa and the Democratic Republic of Congo before reaching their final destination in West Africa.

"People are skinned and the skin is used for their rituals. But fortunately they are caught by the police," Ms Machube said.

Murder charges

In 2001 police broke a skin-smuggling ring and 13 people were charged with murder.

A total of six young people are thought to have been killed and skinned in the Mbeya region of south-western Tanzania.

Ezekiah Swila was 13-years-old when his body was found skinned at Kisinga village.

Three more cases followed in Ileje and Mbozi, both districts in Mbeya, near the Zambian border.

The victims were identified through their DNA.

Ms Machube said that the human skins, skulls and limbs at the trade fair are samples from the police forensic department, and that they are used to let people know that the force now has the technology to scientifically "identify the victims' profiles".

"This is also to educate people that they do not have to to use human skin to become rich," she said.

The prices of the human skins range from $2,400 to $9,600, depending on the age of the victim, police say.