After several hours of Israeli air strikes, daylight has broken in Iran. The Israeli military said the completed strikes were in retaliation for Iranian missile attacks on Israel earlier this month and in April.

The Israeli military has warned Iran against further escalation, saying it “reserves the right to defend its citizens” as fears grow that the long-running confrontation between the two powerful militaries could escalate into a larger regional war – possibly involving the United States.

The Israeli military said it had attacked production sites producing missiles that Iran fired at Israel last year. It is unclear whether these production facilities also produced rockets fired by Iran's proxies Hezbollah, Hamas and Houthi rebels in Yemen, as tensions in the region have escalated since Israel's invasion of Gaza more than a year ago.

Israel also said it struck Iranian air defense sites early Saturday to allow its planes to attack the other targets.

Iran's official Islamic Republic News Agency (IRNA) said parts of military sites in three provinces – Tehran, Ilam and Khuzestan – were hit, but air defense was successful and damage was “limited”.

“The extent of this incident is currently under investigation,” IRNA said. Earlier, videos posted by Tehrans on social media showed explosions in the sky and tracer fire rising from the city as dawn approached.

Images distributed by Iranian state media showed calm on the streets of Tehran, busy traffic and people going about their daily business.

Israel's decision to strike early Saturday morning came after weeks of deliberations within its security cabinet over the nature and scale of such an attack, Israeli officials said.

The United States urged Israel not to attack Iran's energy infrastructure for fear of triggering a wider conflict. According to preliminary reports, Israel appears to have complied with this request.

“This should be the end of this direct exchange of fire between Israel and Iran,” a senior US government official said after the attacks.