Israeli aircraft attacked and killed seven Islamic State (IS) militants in southern Syria's Golan Heights overnight between Wednesday and Thursday, local media and military said.

A military statement confirmed it had opened fire at the militants in the Syrian Golan Heights, near the disputed border between Syria and Israel, and killed seven of them.

Local media identified the militants as operatives with the IS. The Hebrew-language Ha'aretz newspaper reported that they were killed some 200 meters away from the border fence, while still on Syrian soil.

A military spokesperson said in a statement that overnight, "an IDF (Israeli Defense Forces) aircraft fired towards several armed terror operatives in the southern Syrian Golan Heights."

During searches on Thursday morning, explosive belts and an AK-47 assault rifle were found in the area, according to the statement.

Also on Thursday morning, Israeli Defense Minister Avigdor Lieberman told reporters that Israel's air defense forces "are prepared and ready, and prove their capabilities at the moment of truth."

The remark was made during Lieberman's tour at the launch sites of the Patriot missile battery outside Safed.

His tour came after the David's Sling anti-missile system failed its first operational test when it missed missiles launched from Syria last week. Later, two BM-21 rockets landed in the Sea of Galilee after the defense failed to identify and intercept them.

Russian President Vladimir Putin's special envoy to Syria, Alexander Lavrentiev, told TASS news agency on Wednesday that the Iranian forces have withdrawn their heavy weapons in Syria to a distance of 85 km from the Israeli-annexed Golan Heights.