Israel has vowed a forceful military response after accusing Iran of violating a newly declared ceasefire, just hours after U.S. President Donald Trump announced an agreement to halt hostilities between the two nations.

Israel’s Defense Minister said he had instructed the military to launch high-intensity strikes on key targets in Tehran in response to Iranian aggression. “Israel will respond forcefully to any violation of the ceasefire,” Prime Minister Benjamin Netanyahu previously warned.

The escalation came shortly after Israel confirmed a ceasefire with Iran, claiming it had achieved its war aims. Trump had announced the ceasefire on social media Monday evening, declaring it the first halt in fighting in over a week and a half. He noted that Iran’s earlier missile attack on a U.S. base in Qatar had caused no casualties, thanks to early warnings—leaving the door open for diplomacy.

“THE CEASEFIRE IS NOW IN EFFECT,” Trump wrote on Truth Social. “PLEASE DO NOT VIOLATE IT!”

However, the ceasefire quickly unraveled.

After 4 a.m. local time in Tehran, Israel detected missile launches from Iran, prompting air raid sirens across Israel and sending civilians scrambling to shelters. Israeli authorities later confirmed that four people were killed in the attack.

Despite the ceasefire declaration, fighting had continued past midnight. Iranian state media reported Israeli airstrikes in Tehran, while the Israeli military said it intercepted several drones launched from Iran. Residents of the Iranian capital described the bombardment as intense.

Iranian Foreign Minister Abbas Araghchi had earlier signaled a willingness to de-escalate, stating that Iran would stop its attacks if Israel ended its airstrikes. But following the renewed missile launches, Israel treated the move as a breach of the ceasefire and began retaliatory operations.