The official IRNA news agency said residential buildings in the Iranian capital Tehren were hit, naming neighbourhoods in multiple locations in the capital.
State TV reported that children were among those killed in the attack on Tehran.
Reports also say blasts were heard in Natanz city in Iran’s central province of Isfahan, where a key nuclear site is located.
“Loud explosions were heard in Natanz”, which hosts one of the main uranium enrichment facilities, state TV reported.
Israeli Prime Minister Benjamin Netanyahu said the attack on Iran would continue for as long as it takes.
“This operation will continue for as many days as it takes to remove this threat,” Netanyahu said in a video statement, naming the operation “Rising Lion”.
“We struck at the heart of Iran’s nuclear enrichment programme. We targeted Iran’s main enrichment facility at Natanz… We also struck at the heart of Iran’s ballistic missile programme,” he said, adding that Israel had also hit Iranian nuclear scientists “working on the Iranian bomb”.
Reuters quoted an unnamed Israeli defence official as saying that the strikes have likely killed members of Iran’s general staff, including the chief of staff and several senior nuclear scientists.
In the wake of the attacks, Israel closed off the Ben Gurion airport for departures and landing until further notice, according to the airports authority.
Iraq has also closed its airspace and suspended air traffic across the country.
The Chinese embassy in Iran told Chinese citizens in the country that the security situation is “severe and complicated”, and urged them to pay close attention to developments and further enhance security awareness.
US Secretary of State Marco Rubio, meanwhile, warned Iran not to respond to to Israeli strikes by hitting American bases, saying Washington was not involved.
“We are not involved in strikes against Iran and our top priority is protecting American forces in the region,” Rubio said in a statement.
“Let me be clear: Iran should not target US interests or personnel.”
The strikes on Iran came hours after US President Donald Trump publicly said Israel should not do so, saying that this would ruin chances for a peacefully negotiated solution.
A sixth round of talks over Tehran’s nuclear program had been scheduled between the United States and Iran on Sunday in Oman.
“Israel advised us that they believe this action was necessary for its self-defense,” Rubio said, without offering support or criticism of the strikes by the close US ally.
However, the top Democrat on the US Senate Armed Services Committee sharply criticised Israel for the strikes, accusing it of putting the region and American forces at risk.
“Israel’s alarming decision to launch airstrikes on Iran is a reckless escalation that risks igniting regional violence,” Senator Jack Reed of Rhode Island said in a statement. (Agencies)