Iran's Revolutionary Guards threatened to carry out "crushing attacks" against arch-foe Israel if it retaliates for a missile attack by the Islamic republic on Tuesday.

"If the Zionist regime reacts to Iranian operations, it will face crushing attacks," the Islamic Revolutionary Guard Corps (IRGC) said in a statement carried by the Fars news agency. 

The IRGC said the attack was "in accordance with the United Nations Charter".

It said it came "after a period of restraint" following an "attack on the sovereignty" of Iran -- a reference to the killing of Hamas leader Ismail Haniyeh in Tehran in late July.

Iran president hails 'decisive response' to Israeli 'aggression' in missile attack 

Iranian President Masoud Pezeshkian hailed Tuesday night's missile attack against Israel as a "decisive response" to what he called Israeli "aggression".

"In accordance with legitimate rights and with the aim of (establishing) peace and security in Iran and the region, a decisive response has been made to the Zionist regime's aggression," Pezeshkian posted on X.  

Iranian media carried online footage of what they said were missiles being fired at Israel.

State television played upbeat music over the footage as its newscaster spoke of "the brave Iranian people".

Tuesday's attack was Iran's second on Israel in the past six months, after a missile and drone attack in April in retaliation for a deadly Israeli air strike on Iran's consulate in Damascus.

Nearly all of the missiles and drones fired in that attack were intercepted by Israel or its allies.

An Israeli strike on Beirut on Friday killed Hezbollah leader Hassan Nasrallah, whose Lebanese militant group has been armed and financed by Iran for years.

Nasrallah was killed alongside General Abbas Nilforoushan, a top commander of the Quds Force, the IRGC's foreign operations arm.

Iran vowed that Nilforoushan's killing would "not go unanswered".

At last month's UN General Assembly in New York, President Masoud Pezeshkian accused Israel of warmongering as Iran exercised restraint.

He suggested Tehran had held back retaliation for Haniyeh's killing, fearing that it could derail US-backed efforts for a ceasefire in the Gaza war.

"We tried to not respond. They kept telling us we were within reach of peace, perhaps in a week or so," he said.

On Sunday, Pezeshkian said promises by the United States and its allies of a "ceasefire in exchange for Iran's non-reaction to Haniyeh's killing were completely false".

He added that "giving these criminals (Israel) a chance would only encourage them to commit more crimes". 

Iran does not recognise Israel, and has made support for the Palestinian cause a centrepiece of its foreign policy since the Islamic Revolution in 1979.

Tehran hailed its ally Hamas's October 7 attack on Israel, which triggered the Gaza war, but denied any involvement.

Regional tensions have soared since the outbreak of the Gaza war, drawing in Iran-aligned groups from Lebanon, Iraq, Syria, and Yemen.