Militants linked to Islamic State (Isis) have come into direct conflict with Israeli forces for the first time in the terror network's history on Sunday (27 November).

Terrorists in Syria's south opened fire on a military patrol on the Israeli side of the Golan Heights and fired several mortar shells, before an Israeli aircraft took to the skies and struck a gun-mounted vehicle carrying four jihadis inside Syria.

The Israeli military has been careful not to become embroiled in the Syrian Civil War, dismissing the infrequent mortar shells landing in its territory as accidental misfiring between opposing forces, but took firm action on this occasion.

"We don't know all the outcomes of the event. There is great probability there are four dead and the heavy machine gun was destroyed," a senior officer told Israeli news site Haaretz.

The terrorists involved are believed to belong to a regional group known as Shuhada al Yarmouk, which pledged allegiance to IS (Daesh) in 2014, as part of a wider coalition known as the Khalid ibn al Walid Army.

Amos Yadin, the former head of IDF Intelligence and current director of the Institute for National Security Studies, said he believed the attack may have been an effort to win a propaganda victory for an embattled IS.

In a telephone interview with IBTimes UK, Yadin said: "We don't know yet if this is a change in policy of Daesh or just an occasional, unplanned exchange of fire.

"We'll have to watch carefully into the future and see if this is a change of policy from a Daesh perspective. Daesh was very, very careful not to attack Israel because they have enough enemies in Syria.

"If they change their policies and are now attacking Israel, I guess the source is because they are attacked all over so they want to have some propaganda achievement in the Arab world."

Operating roughly 60 miles (100km) south of Damascus, the Khalid ibn al Walid Army has been fighting Bashar al-Assad's forces in Syria but a senior opposition source confirmed to Haaretz their actions in the Golan Heights may be the result of an agreement reached between certain opposition factions and the Assad regime.

The source said the factions were seeking to express their dissatisfaction with the agreement under which they must leave the area and hand over their weapons to regime forces through the attack on Israel.

"There are more than a few armed men who see the agreement as a total surrender because they have no other way out other than via the Israeli or Jordanian border, both of which are blocked," the source said.

The gunfire attack launched at the Israeli Defence Forces was an attempt to make Israel actively involved in Syrian territory, shuffle the deck, and perhaps change the situation, the source said.