This albino grave was sealed to stop people digging up the body
Two mothers in western Tanzania have been attacked by gangs who were after their children who have albinism.
The women were hacked with machetes when the attackers failed to find the two children.
Albinos have been targeted in a series of killings around the country due to a belief their body parts can make magic potions more effective.
At least 30 people with albinism have been killed since March, including a seven-month old baby.
On Wednesday, attackers forced a woman to take them to her home, looking for her nine-year-old daughter in Kibondo District, close to the Burundi border.
The girl was not in the house and so the men attacked the mother.
In the second attack, a gang of four men broke into a house at the Lugufu camp in Kigoma, which hosts refugees from the Democratic Republic of Congo, looking for a child with albinism.
The child, aged two, escaped kidnap after falling under the bed unnoticed.
The women are undergoing treatment for their injuries.
On Thursday, police in south-western Tanzania arrested a man who was attempting to sell his albino wife to Congolese traders.
The BBC's Vicky Ntetema in Dar es Salaam says the attacks appear to have spread from north-western Tanzania, where they were first reported.
The attacks also suggest that there is interest in albino body parts from the neighbouring Democratic Republic of Congo and Burundi, our correspondent says.
The Kigoma regional police commander said the attackers had fled and a manhunt was underway.
The attacks on albinos have been linked to witchdoctors who are peddling the belief that potions made from an albino's legs, hair, hands, and blood can make a person rich.
President Jakaya Kikwete ordered a police crackdown on those involved in the killings in March, and 170 witchdoctors have since been arrested.
But BBC investigations suggest that some police are being "bought off" in order to look away when such crimes are committed.
The prevalence of albinism in Tanzania appears to be high and the Albino Association of Tanzania says the actual number of albinos could be as high as 173,000.
A census is now underway to verify the figures.