Iran warned on Saturday it would defend itself after Israeli air strikes killed at least two soldiers and further stoked fears of a full-scale regional war in the Middle East.

Israel warned Iran would "pay a heavy price" if it responded to the strikes, and the United States, Germany and Britain demanded Tehran not escalate the conflict further.

Other countries, including many of Iran's neighbours, condemned Israel's strikes and some, such as Russia, urged both sides to show restraint and avoid what Moscow dubbed a "catastrophic scenario".

The Islamic republic insisted it had the "right and the duty" to defend itself, while its Lebanese ally Hezbollah said it had already launched rocket salvos targeting five residential areas in northern Israel. 

The Israeli army said 80 projectiles were fired across the border on Saturday.

Confirming its own strikes after explosions and anti-aircraft fire echoed around Tehran, the Israel military said it had hit Iranian missile factories and military facilities in several regions.

The "retaliatory strike has been completed and the mission was fulfilled", while Israeli aircraft "returned safely", a military spokesman added.

Iran confirmed Israel had targeted military sites in Tehran province around the capital and other parts of the country, saying the raids caused "limited damage" but killed two soldiers.

Direct attack 

Israel had vowed to retaliate after October 1, when Iran fired around 200 missiles in only the second ever direct attack against its arch-foe. Most of those missiles were intercepted but one person was killed.

The Israeli retaliation drew condemnation from Hamas, Iraq, Pakistan, Syria and Saudi Arabia, which warned against further escalation. Jordan stated that Israeli jets had not used its airspace. Turkey was one of the most outspoken critics, calling for an end to "terror created by Israel".

Israel is already engaged in combat on two fronts.

Since last month, it has been fighting a war against Hezbollah in Lebanon, including strikes that have killed the group's senior leadership and ground incursions seeking to destroy missile sites.   

And, for more than a year since Hamas's October 7, 2023 attack, Israel has been fighting a war in Gaza that has caused mass civilian casualties in the densely populated Palestinian territory. 

The United Nations has warned the "darkest moment" of that conflict was unfolding, with Palestinians facing a dire humanitarian crisis and daily Israeli bombing. 

Along with Hezbollah and Hamas, Iranian-allied groups in Yemen, Iraq and Syria, have carried out attacks during the fallout from the Gaza war.

At roughly the same time as Israel struck targets in Iran, the Syrian state news agency SANA said an Israeli air attack targeted military positions in central and southern Syria.

'Iranian proxies'

The Islamic Resistance in Iraq, a loose network of pro-Iran factions, claimed responsibility before dawn Saturday for a drone attack against a "military target" in northern Israel.

On Friday, two people died from shrapnel wounds after a Hezbollah rocket barrage into Israel's north, Israeli officials said.

In addition to the residential strikes, Hezbollah said it had fired rockets at Israeli soldiers near the village of Aita al-Shaab in southern Lebanon and at an intelligence base as well as launching drones against Israel's Tel Nof air base south of Tel Aviv.

On Saturday, Lebanon's health ministry said an Israeli strike had killed a Hezbollah-affiliated medic in Bazuriyeh in the south of the country.

US National Security Council spokesman Sean Savett said Israel's response to Iran was "an exercise in self-defence".

He urged Iran to "cease its attacks on Israel so that this cycle of fighting can end without further escalation".

The Israeli military has blamed "Iran and its proxies" in the region for "relentlessly attacking Israel since October 7", when Hamas's attack against Israel triggered the Gaza war.

That attack resulted in the deaths of 1,206 people, mostly civilians, according to an AFP tally of official Israeli figures.

Dozens of hostages seized on that day are still held by militants in Gaza.

Israel's retaliatory bombardment and ground war in Gaza has killed 42,924 people, the majority civilians, according to data from the Hamas-run territory's health ministry, figures the United Nations considers reliable.

In late September Israel turned its focus to Lebanon hitting, Hezbollah targets and leaders and then sending in ground troops. 

Israel says the aim is to make the north of its country safe for tens of thousands of displaced civilians to return.

At least 1,580 people have been killed in Lebanon since September 23, according to an AFP tally of Lebanese health ministry figures.

In April, in its first-ever direct assault against Israeli territory, Iran launched more than 300 drones and missiles. 

Tehran said the barrage was retaliation for a strike on Iran's consular annexe in Damascus that killed members of its Islamic Revolutionary Guard Corps.

Explosions later in April shook Iran's Isfahan province in what US officials, cited by American media, said was Israeli retaliation.

Hospital under threat

Iran said its October 1 missile attack on Israel was retaliation for an Israeli air raid that killed Hezbollah chief Hassan Nasrallah as well as the assassination in Tehran of Hamas political leader Ismail Haniyeh.

On Friday, Gaza's health ministry accused Israeli forces of storming the last functioning hospital in the territory's north in a raid it said left two children dead.

The Israeli military said its forces were operating around Kamal Adwan Hospital in north Gaza's Jabalia refugee camp but it was "not aware of live fire and strikes in the area of the hospital".

The Israeli military says it is seeking to destroy operational capabilities Hamas is trying to rebuild in the north.

Also on Friday, Gaza's civil defence agency said Israeli drone strikes killed 12 people waiting to receive aid near the Al-Shati refugee camp.