Mystery still swirls around the assassination of a top Iranian general in war-torn Syria but details are emerging that suggest he was a key figure in Tehran's campaign to save its beleaguered ally, President Bashar Assad, and in running Hezbollah.

Iran's Islamic Revolutionary Guards Corps initially reported that Brig. Gen. Hassan Shateri, 58, one of its commanders, was killed Tuesday in a rebel ambush in Syria near the Lebanese border as he drove to Beirut.

Later reports say he and two aides were killed Monday near Zabadani, a border town where Hezbollah has a major base and arms depot.

But the Free Syrian Army, one of the main rebel forces battling to topple Assad's minority Alawite regime, claimed Thursday that Shateri, along with several aides, was killed in Israel's Jan. 30 airstrike on Jamraya, near Zabadani.

There were unconfirmed reports at the time that there had been Iranian casualties in the air raid but FSA officials said the death of Shateri and his officers weren't disclosed at the time because to have done so would have had "consequences."

This wasn't explained but the Israelis claimed they blasted a convoy that was transporting Syrian-provided, Russian-built SA-17 anti-aircraft missiles to Lebanon for Hezbollah which would have directly challenged Israel's long-held absolute air superiority over Lebanon for the first time.

Direct Iranian involvement in that alleged operation would have raised the stakes in the 22-month-old Syrian civil war to dangerous levels, that could trigger an Iranian response against the Jewish state at a time when the two rivals were locked in a potentially explosive confrontation over Iran's nuclear program.

It's not clear whether the FSA's purpose on this is to emphasize the extent of Iran's involvement in the war in hopes of persuading the reluctant Americans and their European allies they must drop their refusal to intervene militarily to support the rebel campaign to oust the 43-year Assad regime.

But the welter of often contradictory reports concerning the slaying of Shateri reflects the increasing complexity of the Syrian civil war, which enters its third year March 15 and has killed an estimated 60,000 people.

It also sheds a glimmer of light on the clandestine nature of the conflict that many believe threatens a regional sectarian war and the subterfuge that permeates it.

For one thing, the killing shows Shateri's security was penetrated by his enemies, a serious setback for the Iranians.

The one sure thing that seems to be emerging in the aftermath of Shateri's assassination, although it's still not clear who was behind it, is that he was a man of importance in Iran's efforts to retain its power and influence in the Levant through Syria and Hezbollah.

He was a senior officer in the Al-Quds Force, an elite and covert arm of the Revolutionary Guards who wield immense political and economic power in Iran.

As is usually the case with Al-Quds Force officers operating outside Iran, Shateri concealed his identity, posing as Engineer Hessam Khoshnevis, head of the Iranian mission in Lebanon to help reconstruction of Shiite areas devastated during Hezbollah's 2006 summer war with Israel.

The Iranian Embassy in Beirut, widely believed to be a major intelligence and Al-Quds Force center, identified Shateri as such, initially leading to confusion that two senior Iranian figures may have been killed this week.

Informed sources in Beirut said Shateri/Khoshnevis arrived in Lebanon in 2006 with the title of "Special Representative of the President of the Islamic Republic."

The Saudi-owned daily Asharq al-Awsat reported that Shateri controlled Iranian funds of around $200 million a year that was used to replenish Hezbollah's arsenal after the war and rebuild its missile sites.

As the Revolutionary Guards' representative, he reportedly was a powerful member of Hezbollah's military council who reorganized the group's military forces and command structure.

Shateri, a veteran of Iran's 1980-88 war with Iraq like his powerful chief in Al-Quds Force, Maj. Gen. Qassem Suleimani, is also seen as a key commander of Al-Quds and Hezbollah units operating in Syria.

It's not clear what effect his assassination has had on events in Syria, but he's certain to be replaced by someone as pivotal as himself. Tehran will fight tooth and nail to hold onto Syria.