LITTLE ROCK, Ark. (AP) - The U.S. Attorney for eastern Arkansas has resigned after being asked to do so by the nation's attorney general.

A spokesman said Monday that Chris Thyer resigned Friday. Thyer had been U.S Attorney since Dec. 31, 2010. First assistant Patrick Harris will serve as acting U.S. Attorney.

Thyer said a highlight of his career was combating drug dealers, including during the "Operation Delta Blues" investigation in 2011. He also handled the prosecutions of former Arkansas Treasurer Martha Shoffner, former state judge Michael Maggio, former state Rep. Hudson Hallum and former University of Central Arkansas President Lu Hardin. More recently, he charged people who took money from children's feeding programs.

Federal prosecutors typically resign after a new president takes office, though customarily not as abruptly as in this year's turnover.