Departing from Israel’s usual practice of not commenting on the assassination of opponents, Prime Minister Ehud Olmert's office flatly rejected the charge but legislator Danny Yatom called the assassination “a big achievement for the free world against terrorist organisations.”

Israeli Environment Minster Gideon Ezra observed, “I, of course, do not know who carried out the assassination of Imad, but he should be blessed.”

Mughaniyah, his deputy Talal Hamiya, and Hizbollah leader Hassan Nasrallah topped Israel’s list of most wanted opponents.

Washington had also placed a $5 million price on his head for alleged involvement in the 1983 Beirut bombings of the US embassy that killed 28 and of the US and French barracks that killed 241 marines and 58 French troops. He was blamed by the US for the 1985 hijacking of a US airliner during which a US navy diver was murdered and of the kidnappings of Westerners in Beirut during the 1980s. He was wanted in Argentina for participating in the 1992 and 1994 bombings of the Israeli embassy and Jewish cultural centre in Buenos Aires.

Israel accused him of being behind the 2000 capture of three Israeli soldiers in south Lebanon, the subsequent kidnapping of an Israeli businessman in Beirut, and the seizure of two soldiers on the border in 2006 which prompted Israel’s 33-day onslaught on Lebanon.

A Shia born in 1962 and raised in south Lebanon during Israel’s harsh occupation of the region, Mughaniyah joined Yasser Arafat’s Fatah organisation at 17 and served in Force 17, the police commandos. He became a leading figure in the Lebanese Islamic Jihad organisation founded during Israel’s invasion of Lebanon in 1982 and later shifted to the more mainstream Hizbollah. One brother was killed in a CIA-organised attack in Beirut in 1984 and another in an attempt on Mughaniya’s life in 1994. He escaped at least 20 attempts and had plastic surgery to alter his appearance at least twice. He was a shadowy figure who spent most of his life underground in Beirut or moving between Damascus and Tehran. In the 1990s, he is believed to have become an Iranian intelligence asset.

Hizbollah might retaliate for his murder but Ibrahim Mussawi, editor of the movement’s newspaper, said it will “not react hastily”.

There have been several bomb attacks in Damascus in recent years, most carried out by  religious fundamentalists who seek to overthrow the secular Baathist regime.