TEHRAN, Iran (AP) — Iran struck back at the United States for the killing of a top Iranian general early Wednesday, firing a series of surface-to-surface missiles at an Iraqi air base housing U.S. troops and warning the United States and its allies in the region not to retaliate.

U.S. officials confirmed airstrikes at the air base. There was no immediate word on injuries.

Iranian state TV said the attack was in revenge for the killing of Revolutionary Guard Gen. Qassem Soleimani, whose funeral Tuesday in his hometown of Kerman prompted angry calls to avenge his death, which drastically raised tensions in the Middle East.

Iran’s Revolutionary Guard warned the U.S. and its regional allies against retaliating over the missile attack against the Ain Assad air base in Iraq’s western Anbar province. The Guard issued the warning via a statement carried by Iran’s state-run IRNA news agency.

“We are warning all American allies, who gave their bases to its terrorist army, that any territory that is the starting point of aggressive acts against Iran will be targeted,” The Guard said. It also threatened Israel.

Ain Assad air base is in Iraq’s western Anbar province. It was first used by American forces after the 2003 U.S.-led invasion that toppled dictator Saddam Hussein. It later saw American troops stationed there amid the fight against the Islamic State group in Iraq and Syria.

State TV said the operation’s name was “Martyr Soleimani.” It said the Guard’s aerospace division that controls Iran’s missile program launched the attack. Iran said it would release more information later.

Wednesday’s revenge attack came a mere few hours after crowds in Iran mourned Soleimani and as the U.S. continued to reinforce its own positions in the region and warned of an unspecified threat to shipping from Iran in the region’s waterways, crucial routes for global energy supplies. U.S. embassies and consulates from Asia to Africa and Europe issued security alerts for Americans. The U.S. Air Force launched a drill with 52 fighter jets in Utah, just days after President Donald Trump threatened to hit 52 sites in Iran.