Jerusalem (AFP) - Israel issued stark warnings on Sunday over Iran's presence in neighbouring Syria after a confrontation threatened to open a new and unpredictable period in the country's seven-year civil war.

Israel carried out major air raids in Syria on Saturday, including against what it described as Iranian targets -- the first time it had publicly acknowledged doing so since the war began.

The raids came after an Israeli F16 fighter was shot down by Syrian air defences. The pilots survived, but it was Israel's first loss of a warplane in battle since 1982.

"We inflicted on Saturday a heavy blow to Iranian and Syrian forces," Prime Minister Benjamin Netanyahu said at the start of Sunday's cabinet meeting.

"We made clear to everyone that our rules of engagement will not change in any way. We will continue to harm anyone who tries to harm us. This was our policy and this will remain our policy."

Other Israeli ministers spoke of refusing to accept Iran entrenching itself militarily in Syria, as Netanyahu has said repeatedly. Tehran denies it is doing so.

While several analysts said they did not expect a further escalation in the coming days, some spoke of the possibility of the Syrian war entering a new phase.

Syria has become more emboldened to try to stop Israeli strikes inside the country, while Israel wants to maintain its ability to operate there when it sees fit, said Ofer Zalzberg of the International Crisis Group think tank.

Israel has sought to stay out of direct involvement in the Syrian war, but it acknowledges carrying out dozens of air strikes there to stop what it describes as deliveries of advanced weapons to Lebanese Shiite group Hezbollah.

Israel fought a devastating war in 2006 with Hezbollah, which along with Iran and Russia backs the Syrian regime in the conflict.