TEHRAN, Iran (AP) – Iran has struck back at the United States for killing a top Revolutionary Guards commander, and is calling it revenge for the U.S. killing of Revolutionary Guard Gen. Qassem Soleimani.

U.S. officials say Iran fired a series of ballistic missiles at two military bases in Iraq housing American troops. There were no immediate reports of U.S. casualties.

It’s a major escalation between the two longtime foes, and there were worries the two were close to war. But there were some indications that there would not be further retaliation on either side, at least in the short term.

Some commercial airlines are rerouting flights crossing the Middle East to avoid possible danger amid escalating tensions between the United States and Iran.

Australian carrier Qantas says it’s altering its London to Perth, Australia, routes to avoid Iran and Iraq airspace until further notice. Malaysia Airlines says that “due to recent events,” its planes would avoid Iranian airspace. Singapore Airlines also says its flights to Europe would avoid Iran.

The U.S. Federal Aviation Administration has barred American pilots and carriers from flying in areas of Iraqi, Iranian and some Persian Gulf airspace.

Meanwhile, an Iranian emergency official says a crash has killed all those on board a Ukrainian commercial airliner that took off from Tehran.

The official made the comment after the crash on Wednesday morning. He said rescuers were trying to collect the dead. The plane went down in farmland outside of Iran’s capital, Tehran.

Authorities initially blamed a mechanical problem for the crash. A transportation official in Iran says the plane carried 167 passengers and nine crew members.