Israel and the US have launched a war on Iran, with Donald Trump declaring the start of “major combat operations” and calling on Iranians to rise up against their government.

The US president’s comments came soon after explosions were heard across central Tehran. One apparent strike hit near the offices of the supreme leader, Ayatollah Ali Khamenei. Iran is preparing a “crushing retaliation”, an Iranian official told Reuters.

Explosions rocked northern Israel on Saturday as the country worked to intercept incoming Iranian missiles fired in retaliation. The country had earlier declared a state of emergency, warning civilians to stay near air raid shelters, in anticipation of Iranian drone and missile strikes in response.

Explosions were also heard in Bahrain, home of the US fleet in the Middle East.

Iran and Israel both closed their airspace to civilian flights.

The attack on Iran came hours after Trump said he was “not happy” about the latest negotiations with Iran over its nuclear programme.

The US had built up a large military presence in the region in recent weeks in preparation for an attack, including two aircraft carrier strike groups.

Both the US and Israel called for regime change in Iran and urged a popular uprising after Saturday’s attacks.

Trump called on the Iranian people to “take over your government” in a video on his Truth Social platform. He offered the Iranian military “immunity” should they surrender, or “certain death” if not, and told Iranians the “hour of your freedom is at hand”, urging them to rise up and “take over your government”.

Israel directly addressed Iranians in a Persian-language post on a dedicated Telegram channel.

“Our Iranian brothers and sisters, you are not alone!” the post said, calling on Iranians to upload photos and video of anti-regime protests. “Together we will return Iran to its glorious days.”

Trump and the Israeli military described their attacks as a pre-emptive strike against Iranian threats.

Iranian state television reported that the president, Masoud Pezeshkian, was “safe and sound”, while the Fars news agency said seven “missile impacts” were reported in the Keshvardoost and Pasteur districts of Tehran.

The strikes come weeks after Iranian authorities killed thousands of people as they crushed mass protests, according to rights groups.