The United States and Israel carried out large-scale strikes across Iran on Saturday, after U.S. President Donald Trump urged Iranians to “take over your government,” a striking call that signaled the allies may be aiming to bring an end to the country’s theocratic system after decades of strained relations.

The first strikes of the attack appeared to target the compound home to Iran's 86-year-old Supreme Leader Ayatollah Ali Khamenei in downtown Tehran. It wasn't immediately clear if he was there at the time. Smoke could be seen rising from the Iranian capital.

"For 47 years, the Iranian regime has chanted Death to America and waged an unending campaign of bloodshed and mass murder, targeting the United States, our troops and the innocent people in many, many countries," Trump said in a video posted on social media that sought to justify the attacks. He urged Iranians to take cover during the strikes, but then: "When we are finished, take over your government. It will be yours to take."

The attack quickly expanded beyond Iran. Iran's paramilitary Revolutionary Guard said it responded by launching a "first wave" of drones and missiles targeting Israel, where a nationwide warning was issued as the military said it bring down Iranian fire.