President Donald Trump issued a warning to Iran Wednesday, days after the U.S. Embassy in Baghdad was hit with “several rockets” that Trump says came from Iran.

Trump says U.S. intelligence suggests Iran may be planning further attacks against Americans in Iraq. He warned Iran that he would hold the country responsible if any Americans are killed.

“Our embassy in Baghdad got hit Sunday by several rockets. Three rockets failed to launch. Guess where they were from: IRAN. Now we hear chatter of additional attacks against Americans in Iraq,” Trump tweeted. “Some friendly health advice to Iran: If one American is killed, I will hold Iran responsible. Think it over.”

The Sunday attack saw eight rockets land in the vicinity of the embassy, killing one civilian and causing some structural damage to the compound. No Americans were injured in the attack, according to Secretary of State Mike Pompeo.

U.S. tensions with Iran have escalated throughout 2020 following Trump’s decision to assassinate Iranian General Qasem Soleimani in January. Iran’s top nuclear scientist was also killed in a shoot out late November, though U.S. officials say Israel was behind the killing.

Trump has pushed heavily for U.S. forces to withdraw from Iraq and Afghanistan, signing a peace agreement with the Taliban in February. Despite his election loss, Trump still plans to reduce U.S. troop presence in the two countries to 2,500 total by Jan. 15.