The reservists, all from the 226th Brigade, have been named as Maj. (res.) Evgeny Zinershain, 43, from Zichron Yaakov; Capt. (res.) Sagi Ya’akov Rubinshtein, 31, from Lavi; Master Sgt. (res.) Binyamin Destaw Negose, 28, from Beit Shemesh; and Sgt. 1st Class (res.) Erez Ben Efraim, 25, from Ramat Gan.

The army is investigating whether the building was booby-trapped by a different IDF unit before the four entered it, or if the explosion was the result of an “operational accident.”

According to the IDF, the reservists were on a reconnaissance mission that involved completing engineering tasks in an area the IDF had operated in multiple times before. As part of their mission, they entered an underground basement where weapons were discovered. The explosion occurred while they were attempting to clear the room.