Syrian opposition officials claim the CIA is controlling weapons flow to Syrian insurgents.

"Not one bullet enters Syria without U.S. approval," a Syrian opposition, speaking in Istanbul, told The Australian newspaper.

"The Americans want the (rebellion) to continue but they are not allowing enough supplies in to make the Damascus regime fall."

The allegations, if true, reveal a division between the U.S. State Department, whose stated policy is to assist the removal of the regime of President Bashar Assad and U.S. intelligence services, which are, Syrian opposition forces say, attempting to monitor and manage the tempo of the Syrian insurgency's armed efforts against the regime, The Australian reported Monday.

The Syrian civil war, the murkiest and most violent result of the "Arab Spring" uprisings which began last year, is being assisted by covert agents not only from the United States but Britain, Saudi Arabia, Israel and Iran as Syria devolves into a regional struggle for power in Damascus.

This has turned Turkey's border provinces, which share a 550-mile-long border with Syria, into a miasmic swamp of arms dealers, intelligence operatives and potential jihadis.

Since the political upheaval in Syria, more than 50,000 refugees have crossed the Syrian border into Turkey. Heightening the tensions between the neighboring states, on June 22 the Syrian military shot down a Turkish air force jet.

Ankara subsequently invoked Chapter IV of the NATO charter to convene an extraordinary meeting of NATO members. However, Turkey didn't invoke the charter's Chapter V, requiring the assistance of fellow alliance members, over the Syrian attack.

A Syrian opposition official told The Australian that while the CIA has blocked shipments of heavy anti-tank and anti-aircraft weapons, which Free Syrian Army insurgents maintain are essential in toppling the Assad regime, they have approved supplies of Russian-made AK-47 rifles and 10,000 Russian-made rocket-propelled grenades.

As for logistics the official noted, "The weapons are being carried across the border on donkeys."

There are indications that more advanced military equipment might be reaching the Syrian insurgents. On Monday Syrian, Free Syrian Army rebels said that they shot down a government Russian-made MiG-23 fighter jet near the city of Deir az Zour, and the guerrillas subsequently posted video of the attack on YouTube.

The Syrian government media reported that the jet crashed due to "a technical malfunction" and that the pilot ejected safely and was being sought after "a technical failure occurred while the aircraft was on a training flight," causing the aircraft's controls to "break down," forcing the pilot to eject.

An Israel Radio report and Syrian opposition sources said the Free Syrian Army captured the downed pilot.

Since the "Arab Spring" affected Syria in March 2011, the conflict there has killed as many as 20,000 Syrians, estimates by Syrian opposition groups and the United Nations say.