A war of words erupted in the city’s 911 call center Saturday over allegations two operators made “anti-police” remarks after Rafael Ramos and Wenjian Liu had been shot execution-style by a deranged gunman, sources said. The remarks were allegedly made by a couple of the 911 operators who handle NYPD calls — and two Fire Department dispatchers in earshot got heated in response. A spokesman said the union hadn’t heard anything about a shouting match.