NEW YORK (Reuters) - Public approval of President Donald Trump has dropped to its lowest level since his inauguration, according to a Reuters/Ipsos poll released on Friday, after Trump was accused of mishandling classified information and meddling with an FBI investigation. The May 14-18 opinion poll found that 38 percent of adults approved of Trump while 56 percent disapproved. The remaining 6 percent had “mixed feelings.”  Americans appear to have soured on Trump after a tumultuous week in the White House during which the president fought back a steady drumbeat of critical news reports that ramped up concerns about his administration’s ties to Russia. The week started with revelations that Trump shared highly classified information with Russian diplomats in a private meeting. That was followed by reports that former Federal Bureau of Investigation Director James Comey, whom Trump recently fired, had written memos expressing concerns that the president had pressured him to stop investigating Trump campaign ties to Russia.  Later in the week, the Justice Department appointed former FBI Director Robert Mueller to oversee an independent probe into contacts between Russia and the Trump campaign. Trump has denied colluding with the Russians and called ongoing efforts to investigate him a “witch hunt.” No politician in history, he said, “has been treated worse or more unfairly.”  While Trump remains popular with members of his own party, many rank-and-file Republicans appear to have backed off their support for the president during the past week.  Among Republicans, 23 percent expressed disapproval of Trump in the latest poll, up from 16 percent in the same poll last week. The decline in support from Republicans appears to be a primary reason why Trump’s overall approval rating is now at the lowest level since he took office. The Reuters/Ipsos poll was conducted online in English across the United States. It gathered responses from 1,971 adults, including 721 Republicans and 795 Democrats. It has a credibility interval, a measure of accuracy, of 3 percentage points for the entire group and 4 percentage points for the Democrats and Republicans. (This version of the story has been refiled to delete link to poll results) 