The United States and Israel have launched an attack on Iran, with explosions heard and seen across Tehran.

Several missiles have struck University Street and the Jomhouri area in Tehran, Fars news agency reported. Smoke was seen rising in the city, according to an Al Jazeera correspondent on the ground.

Iran’s semiofficial Tasnim news agency reported that explosions also occurred in Tehran’s northern Seyyed Khandan area. Other Iranian media reported attacks nationwide, including in the western Ilam province.

US President Donald Trump said the joint attacks are aimed at “eliminating imminent threats from the Iranian regime”.

“Short time ago, US military began major combat operation in Iran. Our objective is to defend the American people by eliminating threats from the Iranian regime,” he said.

Israel’s Defence Minister Israel Katz claimed Israel launched the missile attack in order to “remove threats to the State of Israel”.

A US official told Al Jazeera that the attacks were carried out as a joint military operation between Israel and the US, which has assembled a vast fleet of fighter jets and warships in the region to try to pressure Iran into a deal over its nuclear programme. A US official told Reuters that attacks were being carried out by air and sea.

One of the areas targeted in Iran’s capital was near the offices of Supreme Leader Ayatollah Ali Khamenei, reported The Associated Press. Khamenei is not in Tehran and has been transferred to a secure location, according to an official quoted by Reuters.

Al Jazeera’s Maziar Motamedi, reporting from Tehran, said cellphone communications have been disrupted in several areas of the capital. “No calls are possible at present,” he said.

Sirens in Israel

An Iranian official told Reuters that Tehran ⁠is preparing ⁠for retaliation that is set ⁠to be ⁠“crushing”.

As sirens sounded and a state of emergency was declared in Israel, the Israeli military said it had issued a “proactive alert to prepare the public for the possibility of missiles being launched toward the state of Israel”.

The Israel Airports Authority announced its airspace had been closed to all civilian flights and urged the public not to come to the airport.

Meanwhile, the ⁠US embassy in Qatar ⁠implemented shelter-in-place for ⁠all personnel, recommending that all of ‌its citizens do the same until further notice. Iraq’s Ministry of Transport said ⁠it had closed its national airspace.

According to an Israeli defence official quoted by Reuters, the attacks had been planned for months and the ⁠launch date ⁠decided ⁠weeks ago, even as the US and Iran carried out negotiations.

Mehran Kamrava, director of the Iranian studies unit at the Arab Center for Research and Policy Studies and professor at Georgetown University in Qatar, said Israel “appears to have launched an attack designed to derail the negotiations”. (Al Jazeera)