Israeli Defense Minister Yoav Gallant told his American counterpart Secretary of Defense Lloyd Austin that Israel would hold Hezbollah responsible for Saturday’s deadly strike in the Israeli-occupied Golan Heights.

Gallant spoke to Austin on Monday, briefing him on the attack. He shared with Austin the evidence that Israel said indicates Hezbollah’s responsibility for the strike, according to a statement from Israel’s Government Press Office (GPO).

The Iran-backed Lebanese militant group on Saturday “firmly denied” firing projectiles into the village of Majdal Shams, where 12 children were killed and many others injured.

Gallant called the attack a “significant escalation” in the situation.

“Minister Gallant expressed his appreciation to Secretary Austin and the US administration for their clear stance vis-a-vis Hezbollah’s attack, and for their ongoing commitment to Israel’s security,” the GPO said.

Weapons experts told CNN the rocket that exploded on the soccer pitch in the village was likely fired by militants.

Analyzing footage of the explosion and its aftermath, experts told CNN the blast and damage seen on the site were consistent with the types of munitions fired at northern Israel and the Golan Heights from Lebanon and Syria.

US Secretary of State Antony Blinken on Sunday said “every indication” suggests the strike which killed 12 children in the occupied Golan Heights was a rocket fired by Hezbollah.