Israel's planes pass through Lebanese airspace to strike delivery of 'game-changing' weapons

Israeli jets have struck an alleged shipment of advanced missiles in Syria that they say was being sent to the Lebanese organisation Hezbollah, in the latest dangerous escalation of a two-year war.

The airstrike, conducted by Israeli jets which infringed Lebanese air space to fire missiles across the Syrian border, follows several days of incursions by Israeli planes over Lebanon.

Confirming the air raid, sources in Israel say it was approved at a security cabinet meeting on Thursday night chaired by the prime minister, Benjamin Netanyahu. Borrowing the phrase used by Barack Obama to describe any confirmed use of chemical weapons, Israeli officials said they had hit "game-changing" weapons.

Contradictory details emerged about the attack, with some sources saying a convoy had been struck and others a warehouse. It appears that the target was either anti-aircraft weapons or long-range ground-to-ground missiles.

The airstrike came amid an Israeli reserve mobilisation and exercises on its northern border. It was the second Israeli strike this year against Syria, aimed at disrupting arms transfers to Hezbollah, which is an ally of the Syrian president, Bashar al-Assad.

While Israel has stoked fears in recent weeks that the conflict in Syria could lead to the proliferation of chemical weapons, a senior Israeli defence ministry analyst said after the airstrike that Syria's chemical weapons stocks remained controlled by the regime. "Syria has large amounts of chemical weaponry and missiles. Everything there is under [Assad government] control," defence ministry strategist Amos Gilad said in a speech.

Israel has become increasing active in the debate over intervention. It was an Israeli military official who first claimed publicly that western intelligence agencies had evidence of chemical weapons used by the Assad regime.

The raid will be seen not only in terms of its targets, but in its wider significance for the Syria debate. The military correspondent of Israeli newspaper Haaretz argued yesterday: "It will serve the arguments of those who support intervention – opponents of Obama who will be able to argue that the president is demonstrating weakness and appeasement at a time when smaller nations dare to act in Syria."

Obama is considering how to respond to the first uncorroborated suggestions that chemical weapons might have been used in the Syrian civil war. He has described the use of such weapons as a "red line" and the administration is weighing its options, including possible military action.

Netanyahu has repeatedly warned in recent weeks that Israel would be prepared to take military action if chemical weapons or other arms were to reach Hezbollah that would upset the balance of power. Hezbollah, which is allied with Iran, fought an inconclusive war with Israel in 2006 and has been accused of rearming with missiles.

Qassim Saadedine, a commander and spokesman for the rebel Free Syrian Army, said: "Our information indicates there was an Israeli strike on a convoy that was transferring missiles to Hezbollah. We have still not confirmed the location."

A rebel from an information-gathering unit in Damascus that calls itself "Syrian Islamic Masts Intelligence" said the convoy carried anti-aircraft missiles: "There were three strikes by Israeli F-16 jets that damaged a convoy carrying anti-aircraft missiles heading to the Shia Lebanese party [Hezbollah] along the Damascus-Beirut military road."

But Saadedine said he did not think the weapons were anti-aircraft. "We have nothing confirmed yet, but we are assuming that it is some type of long-range missile that would be capable of carrying chemical materials," he said. © Guardian News and Media 2013