The IDF ordered an airstrike on Islamic State’s facility in the south of the Syrian Golan Heights after militants opened small arms and mortar fire on an Israeli patrol on Sunday. Local media said it was the first encounter between the two sides.

An IDF spokesman said that the Monday airstrike targeted “an abandoned military facility, which was previously used by the United Nations and served as a location for [Islamic State or IS, formerly] ISIS to consolidate their offensive forces and operations near the border,” according to the Jerusalem Post.

The military said the bombing came in retaliation to the IS-linked attack on Sunday and was aimed at preventing militants from returning to the compound which would pose “a substantial threat in the area.”

On Sunday, an IDF patrol came under small arms and mortar fire from across the border on Israeli part of the Golan Heights at around 8:30am local time, according to the Jerusalem Post. The gunmen were said to be from the IS-affiliated grouping called ‘Shuhada al-Yarmouk’.

None of the soldiers, all members of IDF’s elite Golani Brigade, was injured, the Israeli military said. In retaliation, the Israeli Air Force scrambled aircraft which spotted and then destroyed a car on the other side of the border, armed with a heavy machine gun.

“Israel will not let Islamic State or any other hostile organization use the chaos of the war in Syria to set up shop on Israel’s northern border,” Prime Minister Benjamin Netanyahu said on Sunday.

On Monday, Netanyahu said that Israel is paying close attention to the developments.

“We will not tolerate even isolated fire and we will respond forcefully and attack our enemies when necessary before they succeed in attacking us,” he said.

“We will not permit radical Islam or any other hostile entity to open a front of terror against us on the Golan,” the PM added, as cited by the Jerusalem Post.

The clash is the first of its kind between Israel and IS-linked militants located in Syria, Israeli media report. The fact that the terrorist group has not staged attacks against Israeli before has given birth to numerous speculations about alleged links between the two sides.

In March, the Times of Israel quoted an article published by IS-run newspaper Al-Naba, which strongly rejected prospect of attacking Israel and lambasted an idea that Palestine was “the Muslims’ primary cause.”

The stunning article argued that “jihad in Palestine is equal to jihad elsewhere,” suggesting there is nothing outstanding in the Israeli occupation of East Jerusalem and the West Bank. Instead, the IS mouthpiece pointed out to the necessity to capture two holy Islamic cities of Mecca and Medina governed by the “tyrannical” Saudi royal family.

Bashar Ja'afari, Syria's chief government negotiator, earlier accused Tel Aviv of cooperating with IS terrorists in the Golan Heights, an area partly captured from Syrians after the 1967 Six-Day War.

“This Israeli provocation...confirms without any doubt the cooperation between Israel and terrorists of Daesh [Arabic pejorative acronym for Islamic State] and [Al-] Nusra Front on the demarcation line between where the Golan is and UN troops are positioned,” he told reporters in April, commenting to Netanyahu’s statement that Israel would never give up control of the Golan Heights.

Since the outbreak of the Syrian civil conflict in 2011, stray shells have landed on Israel’s territory, but reportedly there has been no deliberate attack on Israeli troops until the Sunday assault.