Six members of Lebanon’s Hezbollah movement, including the son of the group’s late military leader Imad Moughniyah, were killed by an Israeli air strike in Syria on Sunday, sources close to Hezbollah said.

The deaths were announced after an Israeli security source told AFP that an Israeli helicopter conducted a strike against "terrorists" near Quneitra, on the Syrian side of the Golan Heights.

Hezbollah said in a statement that six of its members were killed in the attack, including Moughniyah and a top military official, thought to be Mohammad Issa, known as Abou Issa, the senior commander in charge of operations in Syria and Iraq.

Imad Moughniyah was wanted for the 1985 hijacking of a TWA airliner in which a US Navy diver was killed and the 1992 bombing of Israel's embassy in Argentina that cost 29 lives.

The Israeli source did not identify the targets but alleged they were preparing for an attack on Israel, without providing more details.

The strike comes three days after Hezbollahleader Sayyed Hassan Nasrallah said he considered frequent Israeli strikes in Syriaas a major aggression, and that Syria and its allies had the right to respond. Hezbollah has been fighting alongside President Bashar al-Assad’s forces in Syria’s nearly four-year-old civil war.

Quneitra has seen heavy fighting between forces loyal to Assad and rebels including fighters linked to al Qaeda.

Israel has struck Syria several times since the start of the war, mostly destroying weaponry such as missiles that Israeli officials said were destined for Hezbollah, Israel’s long-time foe in neighbouring Lebanon.

Syria said last month that Israeli jets had bombed areas near Damascus international airport and in the town of Dimas, near the border with Lebanon.

Imad Moughniyah, who was on the United States’ most wanted list for attacks on Israeli and Western targets, was assassinated in Damascus in 2008.

(FRANCE 24)