Air raid sirens have sounded across Israel as Iranian missiles struck the country in retaliation for deadly Israeli attacks on nuclear sites and military leaders.

"Don't think that they hit and it's over. No. They started the work and started the war," Iran's Supreme Leader Ayatollah Ali Khamenei said in a recorded message. "We will not allow them to escape safely from this great crime they committed."

The rumble of explosions could be heard throughout Jerusalem on Friday, and Israeli TV stations showed plumes of smoke rising in Tel Aviv after an apparent missile strike. There were no immediate reports of casualties.

The army said dozens of missiles were launched, and the army has ordered residents across the country to move into bomb shelters.

Israel launched a wave of strikes across Iran early Friday that targeted its nuclear program and military sites, killing at least three top military officers and raising the prospect of an all-out war between the two bitter Middle East adversaries. It appeared to be the most significant attack Iran has faced since its 1980s war with Iraq.

The strikes came amid simmering tensions over Iran's rapidly advancing nuclear program.

For years, Israel had threatened such a strike and successive American administrations had sought to prevent it, fearing it would ignite a wider conflict across the Middle East, and that it would be ineffective at destroying Iran's dispersed and hardened nuclear program.