Saeed Kariminejad / Fars News Agency via AP

Iranian mourners carry the flag-draped coffin of Hessam Khoshnevis, identified in some reports as Gen. Hassan Shateri, in Tehran on Thursday. He was killed this week while traveling from Syria to Lebanon.

An Iranian Revolutionary Guard commander has been killed inside Syria by rebels battling Iran's close ally President Bashar Assad, Iranian officials and a rebel leader said on Thursday.

Syrian rebels have repeatedly accused Tehran of sending fighters to help Assad crush the 22-month-old uprising, a charge Iran has denied.

The Iranian embassy in Lebanon said the dead man, Hessam Khoshnevis, was in charge of Tehran's reconstruction assistance in Lebanon. It said he was killed by "armed terrorist groups," a label used by the Syrian government to describe Assad's foes, on the road to Lebanon as he returned from Damascus.

A Syrian opposition commander said the attack was carried out by rebel fighters near the Syrian town of Zabadani, close to the Lebanese border.

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Iran has strongly backed Assad during the uprising in which the United Nations says nearly 70,000 people have been killed. In September Iran's Revolutionary Guard commander in chief said the force was providing non-military support in Syria and may get involved militarily if there is foreign intervention.

Last year Syrian rebels kidnapped 48 Iranians who they said were Revolutionary Guard fighters, and authorities in Tehran described as pilgrims. They released them this year in a prisoner swap with Syrian authorities.

Details of Khoshnevis's killing, which Iranian news agencies said happened on Tuesday, were sketchy, and Iran's envoy to Beirut drew a link with Israel.

"He served the oppressed, supporting the resistance to Israel," the ambassador, Ghazanfar Roknabadi, told reporters as he received condolences from senior Lebanese officials. 

In Tehran, a funeral service held for Khoshnevis on Thursday was attended by senior Revolutionary Guard commanders, Iran's semi-official Fars news agency reported.

Tehran's IRNA news agency said Khoshnevis, identified in some reports as Cmdr. Hassan Shateri, was a military engineer during the 1980-88 conflict between Iran and Iraq, and later operated in Afghanistan.

But officials stressed Khoshnevis was engaged in civilian reconstruction in Lebanon for the last seven years and Lebanon's Al-Safir newspaper said he had been in Syria to study reconstruction plans for the northern city of Aleppo.

Whole districts of Aleppo, Syria's largest city, and other urban centers across the country, have been destroyed in months of entrenched urban warfare. Assad has used airstrikes and artillery to push back rebels, who have become increasingly well armed as the conflict approaches its third year.

The Iranian Revolutionary Guard public relations office said Khoshnevis would be buried in his hometown of Semnan after being "martyred on his way from Damascus to Beirut by mercenaries."

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