By Katy Migiro
NYASHANA, Tanzania, March 21 (Thomson Reuters Foundation) - As Tanzanian widow Ruth Zacharia raised her right arm to protect her skull from a volley of machete blows, her three attackers sliced through her hand.
She fell to the floor; one leg slid into the kitchen fire.
"They said: 'We have been sent by our mother because you killed our father so that you could buy that land'," the 63-year-old recalled, fidgeting with her stiff, scarred right hand.
"I said: 'I am not a witch'... They started cutting me all over."
WATCH: Despite murderous attacks, Tanzania's 'witches' fight for land
Thousands of elderly Tanzanian women have been strangled, knifed to death and burned alive over the last two decades after being denounced as witches.
"They said that (they) are witches... but it was a hidden agenda," said Athanasio Kweyunga, human rights coordinator for the Magu Poverty Eradication Rehabilitation Centre (MAPERECE), a charity helping elderly people in the area.
"The reason is land."
Attacks on women denounced as witches, often by hired thugs or vengeful relatives, continue despite efforts by the government, rights groups and charities to crack down on the killings.
With rapid population growth, land is being subdivided into smaller parcels with each generation. Tired soils, erratic rains and the costs of modern life leave many families in poverty.
Traditionally, widows in Tanzania cannot inherit their husbands' land, but have a right to live out their days on it before it passes on to male relatives. This can create tensions.
"They are supposed to bequeath it when they die -- and they don't die," said Helen Kijo-Bisimba, executive director of LHRC.
"That's why we find some old women are being killed by their own children."
Tanzanians' belief in witchcraft dates back centuries as a way of explaining common misfortunes like death, failed harvests and infertility.
In the first six months of 2016, the police recorded 394 witchcraft-related killings in Tanzania, almost equal to the 425 recorded in the whole of 2015, data from Tanzania's Legal and Human Rights Centre shows.
Superstition is deep-rooted among farming communities living along the shores of Lake Victoria in north-western Tanzania, where most of the attacks take place.
Women with red eyes are often accused of being witches.
But traditional beliefs are often used as a smokescreen, campaigners say, when the main driver of the killings is land.
"There are still sporadic incidents," Sihaba Nkinga, the permanent secretary in Tanzania's ministry for the elderly, said in a phone interview with the Thomson Reuters Foundation.
"The police... haven't got maximum cooperation from members of society where such attacks happen."
Zacharia's troubles began after she bought an acre of land in 2011 near her home in Tanzania's western Magu District.
Another family wanted the land but they were unable to pay for the entire two-acre plot after their father died. So the vendor split it between the two families, who knew each other through the local church.
Zacharia planted rice on her portion but the other family's cows trampled it. One night, she woke to see flames outside her window, as petrol had been doused over the tree overhanging her house. Finally, she was attacked.
"I went through major suffering," she said, taking a break from reading her Bible. "Because they wanted to kill me, they should just be killed."
The perpetrators were arrested in 2014 but were released on bail.
Although Tanzanians believe both sexes can be witches, almost all of the victims of attacks are women.
"The social vulnerability of women is key," said Edward Miguel, a professor of economics at the University of California at Berkeley, who has studied witchcraft killings in Tanzania.
As culture dictates that married women move to their husband's home village, they often become socially isolated and face hostility from in-laws after he dies, he said.
Miguel believes that introducing an old age pension for women could safeguard them from attack.
"Other household members will have an incentive to keep them alive," he said, pointing to the importance of pensions for sustaining many poor families in South Africa.
Miguel's research found that witch killings during the 1990s peaked during periods of drought and flooding, when food was in short supply and the elderly became a burden.
As people interpret reality through the lens of their faith, they believed their attacks on witches caused the improved harvests that followed years of crop failure, he said.
"It's really no different than any other religious belief," he said in a Skype interview.
"It empowers them in a very uncertain world."
Witchdoctors, whose good magic counters the bad magic of witches, have also been widely blamed.
The genitals were cut off many elderly 'witches' corpses for use by witchdoctors in good luck charms, said Joseph Mbasha, Tanzanian spokesman for the charity HelpAge.
"You can mix them up with herbs so that (the witchdoctor) can cleanse you (of a suspected curse) and you could be lucky," he told the Thomson Reuters Foundation.
The region is also notorious for murders of people with albinism, with their body parts also being used in witchdoctors' lucky charms.
Although it is proving hard to stop the killings, police in Magu District say they are seeing a downward trend.
Murders of elderly people in the district have fallen to less than one a month from one each day a decade ago, said Philipo Mziray, commanding officer at Magu police station, dressed in a khaki uniform and black beret.
Rights groups, like MAPERECE, are teaching people about the medical, rather than supernatural, causes of death, such as AIDS and malaria, and the harmful consequences of witchcraft allegations.
After a two months in hospital and lengthy physiotherapy, Zacharia now helps her elderly neighbours report abuse and encourages younger people to take care of their parents.
"If we keep quiet, the oppression will continue," she said, watching chickens fight over grain in her front yard.
"It's better now because people have got knowledge."
The International Women's Media Foundation supported Katy Migiro's reporting from Tanzania