Iran’s powerful Islamic Revolutionary Guard Corps (IRGC) has warned that it is about to launch what it described as the “most devastating offensive operation in the history of the Islamic Republic of Iran.”

The announcement comes hours after Iranian state media confirmed the martyrdom of Supreme Leader Ayatollah Ali Khamenei, dramatically escalating tensions across the Middle East.

According to Iran’s Fars news agency, the IRGC said the offensive would begin “in just moments.”

The statement declared that the operation would target “occupied territories [Israel] and American terrorist bases” across the region.

The warning signals a major military escalation following days of missile exchanges and airstrikes between Iran, Israel and the United States.

Retaliation for Khamenei’s martyrdom

Earlier, Iranian state media reported that Ayatollah Khamenei was martyred in joint US-Israeli strikes on his compound. Authorities announced a seven-day national holiday and a 40-day mourning period.

Iranian officials said more than 200 citizens were martyred and hundreds injured in the broader wave of attacks.

The Iranian military vowed revenge, with officials quoted in Russian media saying the “aggressor will be severely punished.”

In a strongly worded statement, the Iranian government declared: “The oppressors will know who the revolutionaries are,” framing the coming response as both military and ideological.

Israel has confirmed striking more than 30 targets in western and central Iran, including missile arrays and air defense systems.

Meanwhile, Iranian missile attacks were reported on Israel’s Ministry of Defense building in Tel Aviv, the US consulate in Erbil, and Dubai airport, where several people were injured. The UAE said dozens of missiles and drones were intercepted.

US President Donald Trump has publicly claimed responsibility for the operation that killed Khamenei, calling it “justice” and warning that heavy bombing would continue.

The United Nations Secretary-General Antonio Guterres has condemned the escalation and warned of severe regional consequences.