As lawmakers in Washington react to allegations that the Internal Revenue Service (IRS) regularly targeted conservative groups when reviewing their requests for tax-exempt status, President Obama on Monday vowed to find out "exactly what happened" at the IRS during the period under scrutiny - and vowed that any wrongdoers would be held "fully accountable" if found to be operating "in anything less than a neutral and non-partisan way."

Mr. Obama, speaking at a joint press availability with British Prime Minister David Cameron, said he first learned about the allegations last Friday, reading about them in "the same news reports that I think most people" did.