The Lebanese Shia group Hezbollah has confirmed the deaths of several fighters, including the son of a slain military leader and a senior commander, in a Israeli air attack in the Syrian province of Quneitra.

In 2009, Jihad Mughniyeh was during a rally held in Beirut to mark the anniversary of the killing of his father, Imad [AFP]

A Hezbollah statement said an Israeli helicopter fired missiles on Sunday at Jihad Mughniyeh's car in Quneitra, near the Israeli-occupied Golan Heights, killing a total of six members of the group.

Mughniyeh, 20, was the son of Imad Mughniyeh, who was killed in the Syrian capital Damascus in 2008, also in a suspected Israeli attack.

Imad Mughniyeh was on the most-wanted list of the US for attacks on Israeli and Western targets until his killing.

"Mohamad Issa, the chief of Hezbollah operations in Syria, who died in the air strike, is also a big name, making this a major strike on Hezbollah," Al Jazeera's Nicole Johnston, reporting from Beirut, said.

"The group says there will be retaliation for the attack."

Iran's semi-official Tabnak news site reported that the air assault also killed several Iranian troops, who along with Hezbollah - a Lebanese political group with a powerful military wing and close ally of Tehran - are backing Syrian forces loyal to Syrian President Bashar al-Assad against rebels.

The Iranian Revolutionary Guard and Syrian Observatory for Human Rights, a UK-based rights group, both said Mohammad Allah Daddi, an Iranian commander, had been killed in the attack.

Notes From The Field: Al Jazeera's Nour Samaha in Beirut

The Israeli strike comes days after Hassan Nasrallah vowed in an extended interview against Israel making any "stupid" moves against Lebanon and Syria. He promised the movement would retaliate against any Israeli attack in both Syria and Lebanon, adding that the party's missiles can hit any area in Israel.

While Jihad Mughniyeh was not a top level member in the movement, his death is significant because he is the son of slain Hezbollah commander Imad Mughniyeh, who was assassinated in Damascus in February 2008. Mohammad Issa was said to be a high-level commander for the party in the Golan Heights.

Al Jazeera spoke to sources in the party who said there would be "calculated retaliations" for the latest attacks, "at any time and any place".

The Hezbollah-run al-Manar news channel said that the Israeli attack suggest "the enemy has gone crazy because of Hezbollah's growing capabilities and it could lead to a costly adventure that will put the Middle East at stake". 

Israeli Channel 10 television quoted an official Israeli source as confirming the country's role in the attack.

Israel's Ynet news website also quoted a military source as saying that the operation targeted "terrorists who intended to attack Israel".

"This is the seventh time Israel has attacked targets close to its borders since the war in Syria started," Al Jazeera's Nisreen El-Shamayleh, reporting from the Jordanian capital Amman, said.

A statement on al-Manar television said the fighters were killed during a field reconnaissance mission in Mazraat Amal, a village in Quneitra.

Funerals plannned

Al Jazeera's Nicole Johnston, reporting from Beirut, said large funerals were expected in southern Beirut on Monday.

"Jihad Mughniyeh will be buried today (Monday) in Dahyeh, a southern area in Beirut, which is a stronghold of Hezbollah... On Tuesday we expect more funerals in the south of Lebanon," Johnston said.

"Most people we've spoken to on the streets don't seem to think that there would be an immediate reaction from Hezbollah.

"They think it's unlikely that Hezbollah would want to escalate the situation with Israel right now, as they are already fighting a war inside Syria. The last thing they would potentially do is to open up another front."

The incident happened three days after Hassan Nasrallah, the Hezbollah leader, said he considered frequent Israeli attacks in Syria as a major aggression, and that Syria and its allies had the right to respond. 

Nabil Boumonsef, a columnist at the Lebanon newspaper an-Nahar, said he believed the strike was a direct response to Nasrallah's speech and could lead to a backlash.

"Killing the son of Mughniyeh is dangerous. I do not think that the group can be quiet now, now that the father and the son are killed. I expect that it will do something," he said.