A Jerusalem community center inadvertently printed Independence Day fliers with the city's logo that include a look-alike Palestinian flag inserted by an Internet hacker, city officials said Sunday. About 20 advertisements, which were put up by the Givat Shaul community center throughout the neighborhood, include a small Palestinian flag next to a picture of prime minister David Ben-Gurion. They were subsequently removed. The Ben-Gurion picture used in the advertisement was taken from a Web-based photo archive that had been broken into by Internet hackers, without being noticed by graphic artists or local officials, the heads of the community center said. "A serious mishap occurred in the preparation of the Independence Day announcement, which was prepared by an external provider, as a result of the infiltration by malevolent sources into the Internet photo archives," the community center said in a statement. "We are stunned, hurt, and apologize for the grief caused to us all." The municipality called the incident "very severe." "It should be pointed out that this was not a municipal advertisement, but a private neighborhood one that included the city's logo without its permission," the municipality said.