Staff Sergeant Avitar Moshe Torjamin, 20, was killed Tuesday morning in the Gaza Strip, the army announced Tuesday afternoon.

The circumstances of his death remain unclear.

The Beit She’an resident and paratrooper was promoted posthumously to the rank of sergeant.

The latest death brings the number of IDF soldiers killed during Operation Protective Edge to 28.

Nine soldiers were killed in heavy fighting on Monday, both in the coastal enclave and in Israeli territory, in a number of separate incidents.

Sgt. First Class Oded Ben-Sira, 22, from Nir Etzion in northern Israel, who served in the Nahal Brigade, and Master Sergeant Ohad Shemesh, 27, from Beit Elazari were killed during clashes in Gaza on Monday afternoon.

Earlier Monday, seven IDF soldiers were killed battling Hamas on the Israeli side of the border and inside Gaza, the IDF said. Four of them were killed during a pre-dawn tunnel infiltration into southern Israel in which Hamas terrorists planned to attack Kibbutz Nir Am, military sources said.

The seven were named as Lt. Col. Dolev Keidar, 38, from Modi’in; SSgt. Tal Ifrach, 21, from Rishon Lezion; SSgt. Yuval Dagan, 22, from Kfar Saba; Sgt. Nadav Goldmacher, 23, from Beersheba; SFC. Bayhesain Kshaun, 39, from Netivot; Sec. Lt. Yuval Haiman, 21, from Efrat; and SS  Jordan Bensemhoun, 22, from Ashkelon.

Four of the seven were killed by a rocket-propelled grenade, fired by Hamas gunmen who emerged from a tunnel dug from Gaza into Israel near Kibbutz Nir Am. The Hamas cell, clad in IDF uniforms, emerged from the tunnel, and waited for an approaching IDF jeep before opening fire, killing the IDF officer and three other soldiers in the vehicle.

The jeep had been sent to the scene as information on the infiltration was received.

Simultaneously, Hamas opened diversionary fire across the border.

Troops from the Nahal Brigade converged and killed 10 of the Hamas gunmen. Two of the gunmen may have escaped back into Gaza.

“We paid a heavy price, but we averted a grave disaster,” said Sami Turgeman, the general in charge of the IDF’s Southern Command. “There is no Iron Dome protection against tunnel infiltration.”

The three other Israeli soldiers were killed in Shejaiya. Two were hit by an anti-tank missile fired into a building. Like the 13 IDF soldiers killed there overnight Saturday-Sunday, they were members of the Golani Brigade. The third may have been killed by IDF forces in error.

Five soldiers died on Friday and Saturday. Sgt. Eitan Barak, 20 was killed overnight Thursday-Friday in circumstances that remain unclear but are suspected to be a friendly fire incident. Sgt. Adar Barsano, 20; Major (res.) Amotz Greenberg, 45, were killed Saturday when Hamas gunmen infiltrated into Israel opening fire on troops. Sgt. Bnaya Rubel, 20, was killed after a Hamas gunman emerged from a tunnel in Gaza and opened fire and Second Lieutenant Bar Rahav, 21 was killed by an antitank missile fired at a paratrooper position in Gaza Saturday.