The rights group condemned the "increasingly frequent attacks" against Palestinian villagers on Monday and urged the Israeli government to investigate all violent incidents, in particular the recent spate of cases of poisoning fields that has affected scores of Palestinian livestock.

"In recent weeks, toxic chemicals have repeatedly been spread on fields located near the villages of Tuwani, Umm Faqara and Kharuba in the southern Hebron region," Amnesty said in a statement, referring to areas in the southern West Bank.

"Scores of sheep as well as other animals have been contaminated by toxins and several have died.

"Palestinian farmers have been forced to quarantine their flocks and stop using the milk, cheese and meat for them, effectively depriving them of their livelihood."

Poisoning spree

Since the first instance of poisoning was discovered in late March, other fields had also been contaminated, all of them in areas under Israeli security control, the rights group said.

"Scores of sheep as well as other animals have been contaminated by toxins and several have died ... effectively depriving [Palestinian farmers] of their livelihood"

Amnesty International

Until now, however, the Israeli authorities had not decontaminated the fields, nor had they investigated the perpetrators, who were enjoying impunity, the group said.

West Bank police spokesman Shlomi Sagi confirmed that despite a month-long investigation into the initial instance of poisoning, no arrests had yet been made.

Earlier this month, Muhammad Uanam, head of the Palestinian agricultural ministry in Hebron, said 82 heads of cattle had been poisoned, 20 of which died later.

Tests carried out showed the poison was a highly toxic substance called fluoroacetamide. First used as a rat poison, the substance is classified as a dangerous pesticide.