Israel fired artillery shells at a target in Syria early Monday morning after a mortar shell from the war-torn country hit Mount Hermon, opening a second front hours after returning fire into Gaza.

The mortar into Israel’s Golan Heights, which landed near an Israel Defense Forces position, caused no injuries or damage. The army said it was investigating whether the fire was intentional or an errant shell.

Israeli forces responded by firing artillery at the source of the mortar.

“This attack is a blatant violation of the sovereignty of the State of Israel,” IDF spokesman Peter Lerner said.

“We regard this attack with utmost severity,” he added.

Lerner initially indicated that Jerusalem would file a complaint with the United Nations Disengagement Observer Force, but later retracted that statement.

The incident followed an IAF strike on two targets in the Gaza Strip earlier Monday morning after two rockets from the Hamas-ruled territory hit open areas in southern Israel.  

The Israel-Syria border region has seen intermittent exchanges of fire throughout the war in Syria.

Although Israel has largely attributed these incidents to stray fire from clashes in Syria, there have been attempts to target Israeli soldiers.

In May, four IDF soldiers were injured by a roadside bomb in the Mount Hermon area.

That incident occurred outside the Druze town of Majdal Shams, after the soldiers apparently spotted a suspicious person near the border fence and approached to investigate.

In March, two Katyusha rockets were fired at the Israeli Hermon area.