Iran launched a ballistic missile attack on two Iraqi bases housing U.S. troops in the early hours of Wednesday, January 8, CNN reports.

More than a dozen missiles struck the al-Asad airbase and another base in Erbil, both Iranian and American sources confirmed the reports.

So far it seems that there were no casualties. U.S. military sources said troops were given enough warning to reach shelters before the missiles struck.

The attacks were Iran's response to the killing of top Iranian General Qasem Soleimani by the United States in Baghdad.

Iran called the U.S. attack an "act of war" and "state terrorism" and vowed a response.

After Iran's attacks, foreign Minister Mohammad Javad Zarif tweeted that Tehran did not "seek escalation or war."

“Iran took & concluded proportionate measures in self-defense under Article 51 of UN Charter targeting base from which cowardly armed attack against our citizens & senior officials were launched," he tweeted.