Last week a video emerged showing an undercover Israeli security unit attacking, shooting and arresting Palestinian protestors. The agents, dressed in jeans and t-shirts, with kaffiyehs over their faces, had reportedly infiltrated a group of rock throwing youths for around 30 minutes before turning and opening fire on them. Within seconds they were backed up by a number of Israeli soldiers in full uniform.

The agents involved in the attack were part of an elite undercover unit called “Duvdevan”. IDF spokesperson Peter Lerner confirmed the participation of the unit later that day, posting the army’s own clip on Twitter.

The unit, and others similar, are known collectively as 'Mista’arvim’ in Hebrew or “Musta’rabeen” in Arabic, which literally means “Arab pretenders”. These elite “counter-terrorism” units impersonate Palestinians and infiltrate Palestinian communities. Members undergo rigorous training on things such as cultural habits and local dialect in-order to make them indistinguishable when inside a Palestinian community. Disguises donned by agents in the past have included things as ludicrous as dressing as elderly men or Palestinian women cradling pretend babies.

Although little is known about the Mista’arvim, over the years it has been thought to consist of four selective units, two of which belong to the Israeli army; the Duvdevan (Hebrew for cherry) which work in the West Bank, and the second Shamshon (Samson) in the Gaza Strip. The third unit reportedly belongs to the border police and the fourth operates strictly in the Jerusalem area belonging to the Israeli police.

Undercover units had been used to gather information for the Israeli government since its establishment, however during the First Intifada, their role moved away from intelligence gathering. In 1986, shortly before the outbreak of the First Intifada, Duvdevan was established with a main objective to identify, locate, capture, or kill terrorists in the West Bank. Its operational scope grew following the Oslo Accords and the IDF’s withdrawal from territories that were placed under Palestinian Authority control.

After the outbreak of the Second Intifada, Duvdevan continued to operate in the West Bank and at the peak of its activity, according to a report by The Israeli Democracy Institute, was conducting operations on a daily basis.

A group that compiled a report on the Mista’arvim, first recorded the use of undercover units to kill targeted Palestinian in 1987. Palestine Human Rights Information Centre believe this method was then secretly adopted as policy in the first months of the first Intifada, under the authority of the then Minister of Defence Yitzhak Rabin.

During the first four years of the First Intifada 75 Palestinians were killed by Israeli undercover agents or civilian disguised soldiers. PHRIC documented 29 cases in 1991, the fourth year of the intifada, and found that none of the victims had been engaged in combat when they were killed, eleven were taking part in non-violent demonstrations, whilst 14 were carrying out normal daily activities. In all cases no warning was given nor was any effort to apprehend the victim before shooting, according to PHRIC.

Their role as “hit-men” is not confined to the Intifadas. In 2008, soldiers disguised as Palestinians executed four Palestinians in Bethlehem, West Bank. “These men were fighters, but they were not in a combat situation at the time. They were sitting in a car, waiting for their dinner. The Israeli special forces drove up, disguised as Palestinian civilians, and opened fire without warning,” said Jared Malsin, a journalist from Ma’an news agency who had met with the men hours before their killing. “It was the moral equivalent of a team of Palestinians, disguised as Israelis, driving an Israeli car into Tel Aviv and gunning down four off-duty Israeli soldiers.”

The activities of Israel’s undercover units have always been shrouded in secrecy. In 1988 three journalists from Reuters and the Financial Times had their press cards removed after writing pieces on the existence of undercover squads operating in the West Bank. It wasn’t until 1991 that they were officially recognised by the army when Israel TV broadcast a censored 15 minute segment produced in cooperation with the IDF. The broadcast combined tape taken by the units who were disguised as Palestinian men and women in search and arrest operations in unnamed West Bank villages.

Their existence appears to violate both international law and Israel’s own military rules. As the human rights group al-Haq emphasized in a report, disguising military agents in civilian clothes amounts to perfidy, one of the most serious crimes of international law. Extrajudicial assassination, such as the 2008 incident, is also illegal under International Law. Israel’s own Manual on the Rules of Warfare (2006) states that it is forbidden to “adopt the disguise of a non-combatant civilian.”