Israel hit back at Iran early on Saturday, with its military saying it was conducting strikes against military targets in response to Tehran's attacks on Israel.
The Middle East has been on edge in anticipation of Israeli retaliation for a ballistic-missile barrage carried out by Iran on Oct. 1, in which around 200 ballistic missiles were fired at Israel, Iran's second direct attack on Israel in six months.
"In response to months of continuous attacks from the regime in Iran against the State of Israel – right now the Israel Defense Forces is conducting precise strikes on military targets in Iran," the Israel Defense Forces said in a statement.
Israel says it has the right and duty to respond to attacks from Tehran and its proxies, which have included missile strikes launched from Iranian soil.
"Our defensive and offensive capabilities are fully mobilized," it added.
The scope of the attack was not immediately clear.
Iran's state TV said several strong explosions were heard around the capital Tehran. Semi-official Iranian media said explosions were also heard in the nearby city of Karaj.
The Tasnim news agency said that "nothing has been reported about hearing the sound of rockets or airplanes in the sky of Tehran so far".
State TV cited unnamed Iranian intelligence officials as saying that the origin of the loud explosions "could be from the activation of Iran's air defense system."
Iranian authorities have repeatedly warned Israel against launching an attack, saying any strike on Iran would be met with a stronger retaliation.
The United States was notified by Israel ahead of its strikes on targets in Iran but was not involved in the operation, a U.S. official told Reuters.
"We understand that Israel is conducting targeted strikes against military targets in Iran as an exercise of self-defense and in response to Iran's ballistic missile attack against Israel on October 1st," said White House National Security Council spokesperson Sean Savett.
Washington is seeking to head off further widening of the conflict. U.S. Secretary of State Antony Blinken said on Wednesday that Israel's retaliation should not lead to greater escalation.
Syrian state TV said explosions were also heard in the Damascus countryside and central region.
Israel's defense minister said this week that enemies would "pay a heavy price" for trying to harm Israel.
In the past few weeks Israel has intensified its offensive against Palestinian militants Hamas in Gaza and its Iran-backed ally Hezbollah in Lebanon. The war was triggered a year ago by Hamas' Oct. 7, 2023, attack on southern Israel.
