The incident occurred on Wednesday when a group of international peace activists were accompanying Palestinian shepherds as they grazed their flocks on their land, which lies near the Havat Maon settlement outpost at the southernmost tip of the West Bank.
According to Sally Hunsberger, a US national working with the Christian Peacemaker Teams (CPT) who witnessed the attack, two settlers approached her and two other Italian peace activists on a hillside near the outpost.
Pointing a gun
The two masked men demanded they hand over their video camera, which one of them had been using to film an incident several minutes earlier in which settlers pointed a gun at the head of another woman activist from CPT.
After they refused, one of the settlers set on the two activists, breaking the Italian's jaw with a kick. The 22-year-old man, who did not want to be identified, was taken to hospital and is suffering from memory loss.
Although the camera was broken during the incident, the activists got clear footage of the two men involved in the earlier incident, which was handed to Israeli police.
In October, two CPT activists were badly beaten by settlers from the outpost as they were accompanying a group of children to school.
A seven-year-old Palestinian girl was also hit around the head with a stick.
There was no immediate response from Israeli police, who are responsible for all settler-related issues in the West Bank.
Relations between the settlers and the Christian activists have never been good.
Jewish settlers, indoctrinated by a staunchly anti-Christian ideology, routinely throw rocks and shout obscenities at them.