Ten children kidnapped in Tanzania have been found dead with their body parts mutilated, authorities told CNN.

Tanzania's deputy health minister Faustine Ndugulile said all 10 children had been missing since December in Njombe district, southwest Tanzania.

Their bodies were discovered last week after police launched a search operation in the area.

"So far, we have found 10 bodies, and most of their private parts and teeth had been removed," Ndugulile said.

"These murders are linked to witchcraft practices because that is the trend for such crimes, where herbalists ask people to get these human parts for money rituals," he added.

The children, some as young as seven, were kidnapped from their homes last month.

Many children have been reported missing by their parents in the community since December, according to Ndugulile, who said the health ministry was also investigating the wave of killings.

"We want to identify the perpetrators, but our focus is to educate the traditional practitioners in the area quickly and those in surrounding communities on the need to stop these acts," Ndugulile told CNN.

The Deputy health minister told CNN that these killings are not linked albino ritual murders which are prevalent in Tanzania and other parts of east Africa.

"These murders are not linked to albino killings," he said. "But it is very sad because they are children and they don't deserve to be used like this," Ndugulile said.

Tanzania has one of the highest rates of albinism in the world, at one in 1,500 people.