The chief of Israel's armed forces has said that the death last year of a top Hezbollah commander in Syria was an assassination by the Iranian-backed Lebanese group itself.

Hezbollah maintains that Mustafa Badreddine was killed near Damascus by artillery fire from rebel groups fighting Syrian President Bashar al-Assad. But a war monitoring group said no rebel shelling occurred in the area at that time .

Israeli Lieutenant-General Gadi Eisenkot told an academic conference on Tuesday that Badreddine's death last May illustrated "the depth of the internal crisis of Hezbollah".

He said Israel "believes that he was killed by his own officers".

"Those findings show to what degree relations between Hezbollah and its patron Iran are tense and complex."



Hezbollah has deployed thousands of fighters in Syria, where Badreddine had led its intervention in support of Assad's forces, which are also backed by Russia and Iran.

Israeli intelligence claims Badreddine had been feuding with Iranian military commanders in Syria over the heavy losses his group had suffered on the battlefield.

In Beirut, Mohammed Afif, a Hezbollah spokesman, said Israel's allegations were "lies that do not deserve comment".

The US government has said Badreddine, 55, was in charge of Hezbollah's military operations in Syria.

He was one of five Hezbollah members indicted by the UN-backed Special Tribunal for Lebanon in 2005 in connection to the killing of former Lebanese prime minister Rafik al-Hariri and 21 others.

Hezbollah denied any involvement in Hariri's killing and said the charges were politically motivated.

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For years, Badreddine masterminded military operations against Israel from Lebanon and overseas, and managed to evade capture by Arab and Western governments.

Israel, which invaded Lebanon in 2006 to fight Hezbollah and has targeted the group in Syria over alleged arms transfers, called his death good news but stopped short of claiming responsibility.

Badreddine was a student of Imad Mughniyeh, Hezbollah's previous military chief, who was considered one of the world's most-wanted terrorists by Israel and the United States. Mughniyeh, who was Badreddine's brother-in-law, was killed in a 2008 car bombing in Damascus that Hezbollah blamed on Israel.

In a letter written shortly after Baddredine's death, Iranian Foreign Minister Mohammad Javad Zarif extended condolences "for the martyrdom of this great jihadist ... who embodied devotion and vigour and was legendary in his defence of high Islamic goals and his defence of the Lebanese people who resist oppression and terrorism".