Israel unleashed airstrikes across Iran for a third day on Sunday and threatened even greater force as some Iranian missiles evaded Israeli air defenses to strike buildings in the heart of the country.

The Israeli Air Force (IAF) says it has destroyed "dozens" of radars and surface-to-air missile launchers as part of the attacks on Iran's air defence systems in the west of the country. Calling it a "large-scale strike", the IAF says this forms part of ongoing operations to damage Iran's air defence systems and those of its proxies.

Russia has maintained a delicate balancing act in the Middle East for decades, trying to navigate its warm relations with Israel even as it has developed strong economic and military ties with Iran.

While Israel and Iran trade attacks, Palestinians in Gaza have been struggling to find food, connect to the internet and survive airstrikes.

President Donald Trump told Reuters in a phone interview on Friday that it was unclear if Iran still has a nuclear program following Israeli strikes on the country. Trump told Reuters the U.S. still has nuclear talks planned with Iran on Sunday but that he is not sure if they will still take place.

Israeli emergency services have said at least two people were killed in the strikes and dozens of people are injured.