Nearly two thirds of all Americans do not know in what year US invaded Iraq, and less than half have an idea about the US casualty figures in Iraq, latest Pew Research poll shows.

Only 38% of a nationally representative sample of 1,017 American adults were able to correctly state that US invaded Iraq in 2003, while more than a third of the respondents incorrectly picked the year of the invasion was 2002, while 9% and 4% picked 2004 and 2005 respectively.

Less than half of the respondents knew that approximately 3,500 American soldiers were killed since the beginning of the war, with 40% either underestimating the figure, or being ignorant of the number of US casualties in Iraq.

A majority of those surveyed did not know that Shia made up the majority of the Iraqi population, while 70% did not know that Gen. David Petraeus was the commander of US forces in Iraq.

When asked to name the Prime Minister of Iraq, only a little more than a quarter of all Americans gave the correct aswer: Nouri al-Maliki. Incorrect responses included anti-American cleric Muqtada al-Sadr, picked by one in five respondents, and Palestinian President Mahmoud Abbas.