"We will hit every site, every target of the ayatollah regime," Netanyahu said in a video statement on the second day of Israel's air campaign targeting Iranian military and nuclear sites.

"We have dealt a real blow to their nuclear programme" since Friday, he added.

"We have opened a path to Tehran. Very soon, you will see Israeli aircraft -- our air force, our pilots -- in the skies over Tehran," Netanyahu said, shortly after Israel's military reported it had struck 40 targets in the Iranian capital overnight, including missiles and advanced air defence systems.

Israel on Friday launched an unprecedented attack on Iran, hitting more than 200 military and nuclear sites, military spokesman Effie Defrin said, killing top army commanders, nuclear scientists and other senior officials.

"What they have felt so far is nothing compared to what they will feel under the force of our arm in the coming days," Netanyahu said Saturday.

"We are acting with full force to eliminate this dual threat to the State of Israel," he added, referring to Iran's nuclear programme and its ballistic missile capabilities.

Iran said 78 people had been killed and 320 wounded in the first Israeli wave of strikes.

Iran in return launched barrages of drones and missiles at Israel, killing three people, injuring more than 70 others and causing damage in several cities.