Brigadier General Salim Idris, the top commander for the Free Syrian Army (FSA), told Al-Arabiya that if the terror group does not withdraw its fighters from the country, "we will take all measures to hunt Hezbollah, even in hell.”
The FSA is the largest and most organized force within the Syrian opposition, who are battling to oust longtime president Bashar Assad from power.
However, his comments Tuesday reflect growing internal strife between rebel fighters and the various Islamic militant groups who have co-opted opposition forces during the three-year civil war.
Divisions are already forming between al Qaeda's Iraqi cell and Jabhat al Nusra, the main militant group fighting in the country, as well as the Sunni opposition groups that make up the majority of the Syrian rebel forces.
"There are increasing indications though that the moderate Islamists are . . . not comfortable" with [al Qaeda in Iraq] and [Jabhat] al Nusra joining forces, attempting to co-opt the opposition to establish al Qaeda in Syria, Director of National Intelligence James Clapper told Congress in April.
That increasing tension between Islamic radicals and Syrian rebels, comes as animosity between the Sunni-backed opposition and the country's ruling Alawite population, a strain of Shiite Islam the Assad family practices, in western Syria are also reaching a boiling point.
The result prolonged civil war as Sunnis and Alawites square off to fill the power vacuum in the country, mirroring the bloodshed seen in post-Saddam Hussein Iraq, according to Defense Secretary Chuck Hagel.
"The conflict in Syria is intensifying and becoming more sectarian. The possibilities of state fragmentation are increasing, as are the risks of extremism and proliferation," Defense Secretary Chuck Hagel said in a speech in Washington earlier this month.
"The old order in the Middle East is disappearing, and what will replace it remains unknown. There will continue to be instability in the region . . . and we all must adjust accordingly," he added during his address at the Washington Institute for Near East Policy.
Efforts by the FSA to purge the rebel ranks of Islamic extremists come as the European Union has agreed to end an embargo blocking arms shipments to opposition forces.
The State Department on Tuesday applauded the European Union's decision to lift the embargo on weapons sales to Syria, abandoning its earlier stance that more weapons to the region would only further “militarize” the ongoing war.
However, the White House and Pentagon remain adamantly opposed to directly arming rebel factions, out of concern that U.S.-made weapons could end up in the hands of Islamist militants.