A rocket attack hit the US embassy in Baghdad's fortified green zone late Saturday, hours before the start of Iraq's historic election, killing two Americans.

The insurgent missile slammed into the embassy compound after a night-time curfew had come into effect.

A US embassy statement identified the dead as a member of the US military and a civilian. Five Americans were wounded.

At least 21 people were killed in insurgent attacks across the country on the eve of voting in the first election since the fall of Saddam Hussein in April 2003.