TEHRAN - Iran warned it would defend itself after Israeli air strikes killed at least four soldiers and further stoked fears of a full-scale 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.
US President Joe Biden said he hoped "this is the end" after the pre-dawn Israeli strikes, noting that "it looks like they didn't hit anything other than military targets".
Biden had urged Israel to spare nuclear and oil facilities in its retaliatory strikes and the International Atomic Energy Agency confirmed that no nuclear sites were hit.
The European Union called for all parties to exercise utmost restraint to avoid an "uncontrollable escalation".
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".
Iran 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.
Hezbollah later issued evacuation warnings for more than a dozen named locations in Israel, while the Israeli army made similar warnings for two neighbourhoods in southern Beirut.
Lebanon's official National News Agency reported early Sunday that Israel had carried out a fresh raid in Beirut's southern suburbs.
Confirming its own strikes after explosions and anti-aircraft fire echoed around Tehran, the Israeli military said it had hit Iranian missile factories and military facilities in several provinces.
The "retaliatory strike has been completed and the mission was fulfilled", and Israeli aircraft "returned safely", a military spokesman said.
Iran confirmed Israel had targeted military sites around the capital and in other provinces, saying the raids caused "limited damage" but killed four soldiers.
Iran's armed forces general staff said only radar systems were damaged in the strikes and held back from any threat of immediate retaliation.
"While reserving its legal and legitimate right to respond at the appropriate moment, Iran is prioritising the establishment of a lasting ceasefire in Gaza and Lebanon," it said.