Iran's Revolutionary Guard says it accidentally shot down the Ukrainian jetliner that crashed earlier this week, killing all 176 aboard.

The government had repeatedly denied Western accusations that it was responsible for the crash.

The plane was hit hours after Iran launched a ballistic missile attack on two military bases housing U.S. troops in Iraq, in retaliation for the killing of its top general.

The acknowledgment is an embarrassment for Iran's armed forces and is likely to anger the Iranian public.

It also raises new questions about who ordered the strike and why Iran had not shut down its airspace as it braced for U.S. retaliation.