Washington |  Iran struck back at the United States on Wednesday for killing a top Revolutionary Guards commander, firing a series of ballistic missiles at two military bases in Iraq housing American troops in a major escalation between the two longtime foes.

It was Iran's most direct assault on America since the 1979 seizing of the US Embassy in Tehran, and Iranian state TV said it was in revenge for the US killing of Revolutionary Guard General Qassem Soleimani, whose death last week in an American drone strike near Baghdad prompted angry calls to avenge his slaying.

Bloomberg