Jerusalem (AFP) - Prime Minister Benjamin Netanyahu admitted for the first time Tuesday that Israeli forces have been operating in Syria, where the Iran-backed regime is battling rebels including the jihadist Islamic State.

"We occasionally carry out operations in Syria to prevent that country from becoming a front against us," Netanyahu told reporters during a visit to northern Israel.

"We also do everything to prevent weapons, particularly lethal ones, being moved from Syria to Lebanon," he added.

Netanyahu did not provide further details and his comments were the first public recognition that Israel has been active in conflict-riddled Syria.

Several purported strikes have occurred in recent months, targeting alleged Iranian arms transfers from Syria to Lebanon and destined for Israel's arch-foe, the Lebanese Shiite movement Hezbollah.

But these strikes were not officially acknowledged by Israeli authorities.

Israel opposes the regime of Syrian President Bashar al-Assad, which has been battling an armed rebellion since March 2011, but has sought to avoid being dragged into the war in neighbouring Syria.

Russia, an ally of the Assad regime along with Iran, launched an air campaign against his opponents in late September.

On Sunday, Defence Minister Moshe Yaalon said a Russian warplane had recently entered Israeli-controlled airspace from Syria but the intrusion was resolved without incident.

"It was apparently an error by the pilot who was flying near the Golan," Yaalon said.

Israel seized most of the Golan Heights from Syria in 1967 and later annexed the territory in a move never recognised by the international community.

Yaalon said Israel and Russia had made arrangements to avoid clashes over Syria, with the agreement said to include a "hotline" and information sharing.

Netanyahu echoed his comments on Tuesday, saying the Israeli and Russian military forces "are in close coordination to avoid such incidents".

Their remarks came in the aftermath of the downing by Turkey over a Russian warplane which Ankara said had entered Turkish airspace -- a claim denied by Moscow.