Russian President Vladimir Putin condemned Israel's wave of strikes launched at Iran, the Kremlin said on Friday, as he held separate phone calls with Israeli Prime Minister Benjamin Netanyahu and Iranian President Masoud Pezeshkian.

"Vladimir Putin stressed that Russia condemns Israel's actions, which violate the UN Charter and international law," the Kremlin said in a statement, adding that Putin told Netanyahu of his "readiness to provide mediation" to prevent further escalation.

France could help defend Israel against an attack from Iran "if in a position to do so", French President Emmanuel Macron said on Friday.

"If Israel were to be attacked in retaliation by Iran, France, if in a position to do so, would take part in protection and defense operations," he said during a press conference.

Iranian air defenses intercepted "projectiles" over the capital Tehran on Friday, state media said, as Israel vowed to keep up pressure after a wave of strikes on military and nuclear sites.

"Enemy projectiles were intercepted by the Tehran air defense," state news agency IRNA said, with another agency, ISNA, reporting that "the air defense systems of Tehran successfully shot down targets".

Several explosions were heard in Tehran and surrounding areas Friday evening, Iranian state media reported, more than 12 hours after a massive wave of Israeli attacks on the country.

"There were reports of explosions heard in the west of Tehran province," in the cities of Shahriar and Malard and around the neighborhood of Chitgar in Tehran city, state news agency IRNA reported, while Mehr agency reported a blast in Pakdasht southeast of the capital.

Prime Minister Benjamin Netanyahu said he expected "several waves of Iranian attacks" in response to Israeli strikes on the Islamic republic on Friday, saying he had initially planned an attack in April.

"We expect to be exposed to several waves of Iranian attacks," Netanyahu said in a video statement, after Israel struck military and nuclear sites in Iran in the early hours of Friday.

For Israeli Prime Minister Benjamin Netanyahu, a blistering attack on the heart of Iran’s nuclear and military structure distracts attention from Israel’s ongoing and increasingly devastating war in Gaza, which is now over 20 months old.

There is a broad consensus in the Israeli public that Iran is a major threat, and Israel’s opposition leader, Yair Lapid, a staunch critic of Netanyahu, offered his “full support” for the mission against Iran. But if Iranian reprisals cause heavy Israeli casualties or major disruptions to daily life, public opinion could shift quickly.

Israeli leaders cast a blistering attack on the heart of Iran’s nuclear and military structure as necessary to head off an imminent threat that Iran would build nuclear bombs, though it remains unclear how close the country is to achieving that or whether Iran had actually been planning a strike. Iran maintains its nuclear program is for civilian purposes only.

"This is a clear and present danger to Israel’s very survival,” Israeli Prime Minister Benjamin Netanyahu claimed as he vowed to pursue the attack for as long as necessary to “remove this threat.”

Israel's military said on Friday it had begun deploying reservists "to all combat arenas throughout the country" after launching a wave of strikes on military and nuclear sites in Iran.

The military said in a statement that it "began to deploy reservists from different units to all combat arenas throughout the country", calling it part of "preparations for defense and offence across all arenas".

The United States is shifting military resources, including ships, in the Middle East in response to Israel's strikes on Iran and a possible retaliatory attack by Tehran, two U.S. officials said Friday.

The Navy has directed the destroyer USS Thomas Hudner, which is capable of defending against ballistic missiles, to begin sailing from the western Mediterranean Sea toward the eastern Mediterranean and has directed a second destroyer to begin moving forward so it can be available if requested by the White House.

Israel targeted leading members of Iran's armed forces on Friday during its unprecedented onslaught hitting military and nuclear targets across the country.

Here is what we know about some of the top figures killed: