Pete Buttigieg, Democratic presidential candidate and former South Bend, Indiana mayor attends a campaign event in Merrimack, New Hampshire, U.S., February 6, 2020. REUTERS/Eric Thayer

WASHINGTON (Reuters) - Pete Buttigieg, a former mayor of South Bend, Indiana, narrowly defeated Senator Bernie Sanders in the Iowa caucuses with all precincts counted, the Iowa Democratic Party said on Thursday, after technical glitches hindered the counting of votes in the fist contest for the Democratic presidential nomination.