Syrian rebels celebrating
Members of the Free Syrian Army celebrate after the rebels captured a string of checkpoints on the borders with Iraq and Turkey. Reuters

Turkey has closed its last open border gates with Syria following a counter-offensive by troops loyal to President Bashar al-Assad against rebel forces in Aleppo.

The Ankara government has closed the border crossings at Cilvegözü, Oncupınar and Karkamış, said a Turkish official. Only Syrian refugees will be able to pass the checkpoints.

The move marks a turning point in Syria's civil war, as it means that commercial vehicles will no longer be allowed across the border - depriving the country of a key outlet for imports and exports.

Rebels have captured two border crossings between Syria and Turkey, looting and burning dozens of Turkish trucks in the process. Relations between the two countries have been strained since Syrian forces shot down a Turkish F-4 Phantom fighter in June - prompting Turkey to send anti-aircraft missiles to the border.

On 24 July, Turkish prime minister Recep Tayyip Erdogan said that the rebels are "closer than ever to victory" and warned Turkey will respond firmly to any hostility from Syria.

Israel reacts strongly to Hezbollah reports

Israel's foreign minister says the country will act immediately if it discovers Lebanese Hezbollah militants are raiding Syria's chemical or biological weapon arsenal.

The rebel Free Syrian Army claims Syrian forces have moved chemical weapons to border areas.

Responding to these allegations, Avigdor Lieberman told Israel Radio that "for us, that's a casus belli, a red line."

The Syria regime's arsenal allegedly includes nerve agents, mustard gas, missile systems and a variety of advanced conventional arms, including anti-tank rockets and late-model portable anti-aircraft missiles.

Damascus has sought to reassure international leaders that it will not use its chemical and biological weapons against its own citizens, and Russia's foreign ministry says that Syria has given 'firm assurances' that its chemical weapons arsenal is fully safeguarded.

In Damascus, Syrian authorities have arrested a person in connection with the bomb attack which killed three senior members of Assad's inner circle on 18 July.

The suspect worked at the security headquarters in Damascus, where the explosion occurred.

Syria Civil War: Assad's Forces Descend on Aleppo [VIDEO]