Israel's military said it was striking military targets in Tehran on Wednesday, as AFP journalists reported hearing blasts in the north and east of the Iranian capital.

The Israeli air force "is currently striking military targets belonging to the Iranian Regime in Tehran," the military said in a statement, on the sixth day of the war between the arch foes.

Iran's supreme leader Ayatollah Ali Khamenei said Wednesday the nation would never surrender as demanded by President Donald Trump and warned the United States it would face "irreparable damage" if it intervenes in support of its ally.

The speech came six days into the conflict, with Trump demanding Iran's "unconditional surrender" while boasting the United States could kill Khamenei and fueling speculation about a possible intervention.

Hundreds of people gathered outside a London court Wednesday in a show of support for the provocative Irish rap group Kneecap as one of the singers appeared charged with a terror offense for allegedly promoting Lebanon's Hezbollah.

Liam O'Hanna, 27, known by his stage name Mo Chara, was charged in May after being accused of displaying a Hezbollah flag during a London concert in November.

The United States is setting up a round-the-clock task force to help Americans in the Middle East during the Israel-Iran conflict, officials said Tuesday.

U.S. President Donald Trump met his National Security Council on Tuesday to discuss the Iran-Israel war, the White House said, as the U.S. leader considered whether to join Israel's air campaign against Tehran.

Israel said it struck a nuclear site near Tehran on Wednesday, while Iran said it fired hypersonic missiles as the arch foes traded fire for a sixth day.

Hours after U.S. President Donald Trump demanded Iran's surrender, supreme leader Ayatollah Ali Khamenei vowed his country would show "no mercy" towards Israel's leadership.

U.S. President Donald Trump dramatically stepped up his rhetoric against Iran's supreme leader Tuesday, saying on social media that the United States knows where Ayatollah Ali Khamenei is located but will not kill him "for now."

In another post, Trump also appeared to demand Iran's "UNCONDITIONAL SURRENDER!" as he fueled questions about whether the United States would join Israel's attacks on Tehran's leadership and nuclear facilities.

Air raid sirens sounded in the Tel Aviv area and parts of northern Israel on Tuesday, the military said, after warning of a fresh salvo of incoming missiles fired from Iran.

"A short while ago, sirens sounded in several areas across Israel following the identification of missiles launched from Iran toward the state of Israel," a statement from the military said, with residents of the Tel Aviv area and parts of the north urged to seek shelter.

There appear to have been "direct impacts" on the underground part of Iran's Natanz nuclear site during Israel's attacks, the U.N.'s atomic watchdog said on Tuesday.

"Based on continued analysis of high resolution satellite imagery collected after Friday's attacks, the IAEA has identified additional elements that indicate direct impacts on the underground enrichment halls at Natanz," the International Atomic Energy Agency said on X, formerly Twitter.

Twenty countries denounced in a joint statement the escalating tensions in the Middle East caused by what they term Israel’s aggression against Iran and called for diplomacy and dialogue to restore stability in the region.

“There’s an imperative need to halt Israeli hostilities against Iran, which come during a time of increasing tension in the Middle East, and to work towards de-escalation, to achieve a comprehensive ceasefire and restoration of calm,” read the statement.