The photo circulating on Facebook, used to warn Palestinians how to spot and avoid Israeli undercover agents.

Online activists posted an image allegedly featuring the pictures of several undercover Israeli counter-terror agents who have been tasked with arresting Palestinian rioters amid ongoing clashes with security personnel in the West Bank and east Jerusalem, the Israeli news site Walla reported on Sunday.

So-called mista’arvim are undercover soldiers whose job it is to infiltrate Palestinian society for intelligence-gathering and counter-terrorism efforts, including arrests and law enforcement, and their success depends on their ability to move inconspicuously among Arab communities.

The image posted to social media included a banner reading: “These are the despicable mista’arvim. Spread these pictures of them around. And you, children of Jerusalem, remember their faces.”

The post came amid heightened tensions between Palestinians and Israelis over the last several weeks. Mista’arvim have played a crucial role in attempting to stop riots, rock-throwing and firebomb attacks before clashes erupt. Palestinian rock-throwers claimed the life of a 60-year-old man in Jerusalem last month, after hurling stones at his vehicle caused him to lose control and crash into a telephone pole.

According to Walla, Palestinian demonstrators have begun chanting “tuck in your shirts” at riots and demonstrations, apparently to single out undercover officers whose weapons would become apparent were their shirts tucked in. The report also stated that Israeli police had also begun using undercover agents to make arrests among the Israeli-Arab demonstrations that have erupted in cities across the country, including in Tel Aviv-Jaffa, Nazareth and Umm el-Fahm.

Last week, a video surfaced, which was reported on in the U.K. Telegraph , showing undercover Israeli officers dressed up like Palestinian rioters — in baggy jeans, long-sleeved solid or striped shirts and crude balaclavas — rushing, tackling and arresting a Palestinian stone-thrower.

A senior Israel Police official told Channel 2 that the undercover Israeli unit was instrumental both in helping prevent attacks — or stop them quickly — and in intelligence-gathering about imminent terrorist threats.

Israel and the Palestinian territories have been convulsed with violence for the past several weeks. On Monday alone, three new Palestinian stabbing attacks against Israelis were reported in neighborhoods of Jerusalem, with one 13-year-old teenager in serious condition. The violence also entered the Gaza Strip, where Israeli air strikes on terror targets in response to a rocket attack from the coastal enclave left a pregnant woman and her three-year-old child dead.