North Korean workers vowed “thousandfold revenge” against the U.S. as part of the first large-scale events to celebrate an anti-American holiday in five years, according to state media Friday, signaling a shift in propaganda strategy after years of censoring and hiding anti-U.S. content.

In a report on the workers’ gathering to mark the June 25 “Day of Anti-U.S. Struggle,” the Rodong Sinmun also said citizens viewed paintings depicting American war atrocities during the 1950-53 Korean War to remind them of Washington’s ongoing hostile policy.