What is Hezbollah's role in the Israel-Hamas war?

Since a new war broke out between Israel and the militant Palestinian group Hamas on Oct 7, the Lebanese militia Hezbollah has expressed solidarity with Hamas through military action.

It has fired missiles, mortars, rockets and explosive drones into northern Israel almost daily, prompting Israel to respond with its own fire.

Now, an escalation of the fighting appears to have edged the two sides closer to all-out war. In addition, Hezbollah has threatened to bring the nearby island nation of Cyprus, where Israeli soldiers have trained, into the hostilities.

Yet, both Israel and Hezbollah have reasons to avoid a full-blown conflict.

WHAT IS HEZBOLLAH?

Shi'ite Muslims in Lebanon formed what would become Hezbollah "Party of God" - in 1982, in reaction to Israel's occupation of the country's south. The movement was inspired by the 1979 Islamic Revolution in Shi'ite-majority Iran, and Hezbollah is heavily influenced by Iran's elite Islamic Revolutionary Guard Corps. Shi'ite Muslims and Sunni Muslims each comprise about 30 per cent of Lebanon's population.

Because it is separate from Lebanon's military, Hezbollah can attack targets without provoking the reaction such a move by a state would precipitate. Still, Israel and Hezbollah have fought repeated battles, including a war in 2006.

On April 13, while Iran conducted an unprecedented aerial bombardment of Israel, Hezbollah launched its own barrage, further testing Israel's air defences. Like Hamas, Hezbollah is designated by the US as a terrorist organisation. The group is thought to have been behind a number of major attacks on US targets in the 1980s.

HOW DOES IRAN SUPPORT HEZBOLLAH?

Iran provides Hezbollah with "most of its funding, training, weapons and explosives, as well as political, diplomatic, monetary and organisational aid", according to the US State Department.