Syria has condemned Israeli airstrikes against targets around Damascus, saying the attacks give direct military support to terrorist groups fighting the government.

The Syrian Foreign Ministry also said in a letter sent to the United Nations and the UN Security Council that "Israeli aggression" killed and wounded several people and caused widespread destruction.

Syria's Government refers to rebels trying to topple President Bashar al Assad's regime as terrorists. It held an emergency cabinet meeting in response to the air strike by Israel.

Yesterday's attack was the third Israeli strike this year on Syrian soil. Israeli warplanes struck areas in and around the Syrian capital, targeting a shipment of Iranian-made guided missiles believed to be bound for Lebanon's Hizbollah militant group.

Damascus-based activist Maath al-Shami said the strikes occurred around 3am. "Damascus shook. The explosion was very, very strong," said Mr al Shami. He added that one of the attacks occurred near the capital's Qasioun mountain that overlooks Damascus.

He said the raid targeted a military position for the elite Republican Guards in charge of protecting Damascus, Mr Assad's seat of power.

The attack, the second by Israel in three days and the third this year, signalled a sharp escalation of Israel's involvement in Syria's civil war.

Syrian state media reported that Israeli missiles struck a military and scientific research centre near Damascus and caused casualties.While the Government tried to use the attacks to taint the rebels by linking them to Israel, the airstrikes still pose a dilemma for an Assad regime already battling a relentless rebellion at home.

If it fails to respond, it looks weak and opens the door to such airstrikes becoming a common occurrence.

But any military retaliation against Israel would risk dragging the Jewish state and its powerful Army into a broader conflict.

The tempo of the new strikes added a dangerous dynamic to the conflict, fuelling concerns that events could spin out of control and spark regional crisis.

Israel's military yesterday deployed two batteries of its rocket-defence system to the north of the country. It described the move as part of "ongoing situational assessments".

A senior Israeli official said Israel launched an airstrike in the Syrian capital but did not give more precise details about the location.

The target was Fateh-110 missiles, which have precision guidance systems with better aim than anything Hizbollah is known to have in its arsenal, the official said.

The airstrikes come as Washington considers how to respond to indications that the Syrian regime may have used chemical weapons in its civil war.

President Barack Obama has described the use of such weapons as crossing a red line and the administration is weighing its options – including possible military action.

Iran, a close ally of the Assad regime, condemned the airstrikes but gave no other hints of a possible stronger response.

Israel has said it wants to stay out of the Syrian war, but Prime Minister Benjamin Netanyahu has repeatedly stated Israel would be prepared to take military action to prevent sophisticated weapons from flowing from Syria to Hizbollah or other extremist groups.

A month-long ware between Israel and Hizbollah in 2006 ended in a stalemate.

The militant group is believed to have restocked its arsenal since that conflict with tens of thousands of rockets and missiles.

Israel is especially concerned that Hizbollah will take advantage of the chaos in neighbouring Syria and try to smuggle advanced weapons into Lebanon.