BEIRUT - A high-ranking member of Iran's Revolutionary Guard Corps was assassinated this week while traveling from Syria to neighboring Lebanon, Iranian media reported Thursday. It was the strongest indication to date that senior Iranian commanders have been dispatched to Syria.

Gen. Hassan Shateri was killed Tuesday by "unknown gunmen," described as "suspected Israeli agents," as he was on the road between the Syrian capital of Damascus and Beirut, the capital of Lebanon, various Iranian news agencies reported.

Iran is a staunch ally of Syrian President Bashar Assad, who is facing an almost two-year-long rebellion against his rule.

Rebel forces and their allies, including the United States, have accused Iran of propping up Assad's regime with extensive military, logistics and financial aid.

The Iranian media accounts did not specify exactly where Shateri was killed, but they labeled the death an "assassination," indicating that he was targeted. If his death occurred in Syria, Shateri would be the first senior Iranian commander publicly known to have been killed in the Syrian conflict.

Iranian opposition websites identified Shateri as a member of the Quds Force, the foreign arm of the Revolutionary Guard. The chief of the Quds Force, Gen. Qasim Sulaimani, accompanied by high-ranking clergymen, personally notified the general's family of his death, Iranian media reported, a fact that seemed to confirm the slain general's link to the shadowy force.

Meanwhile, the Syrian insurgency claimed Thursday to have near-total control of a strategically important province in the country's northeast, home to some of the few remaining domestic oil production facilities that supply fuel for Assad's military forces, after ferocious clashes that lasted for three days.

The rebel assertions about the province, Hasaka, would, if confirmed, be at least the third significant gain by the insurgency this week, following the seizure of Syria's largest hydropower dam and the takeover of a northern military air base with much of its fleet still intact.

Hasaka province includes the ethnically mixed city of Shadadi, one of the 10 largest cities in the country.