Secretary of State John Kerry reacted to a report Thursday that Jews in one restive Ukrainian city were sent notices telling them to register, a development he called "grotesque." Kerry's comments follow a report in Israel's Ynet News that a leaflet was circulating in the eastern Ukrainian city of Donetsk, demanding that Jews register -- as well as provide a list of property they own -- or else face deportation and revocation of citizenship. Pro-Russian activists have asserted partial control over some government buildings in that city. Ynet reported that the notices, sent as the Passover holiday began, were signed by Denis Pushilin, chairman of Donetsk's temporary government -- though Ynet reports that Pushilin confirmed the flyers came from his organization, "but denied any connection to the leaflet's content." The notices reportedly were sent to areas where pro-Russian activists have declared the region as a "people's republic" in defiance of the central Ukrainian government. While questions circulated about the origin of the flyers, Ynet reported the flyers said that because Jewish community leaders supported a Ukrainian nationalist movement and "oppose the pro-Slavic People's Republic of Donetsk," the interim government has decided: "that all citizens of Jewish descent, over 16 years of age and residing within the republic's territory are required to report to the Commissioner for Nationalities in the Donetsk Regional Administration building and register." The notices reportedly demand Jews pay a $50 registration fee. Kerry addressed the flyer reports during a press conference in Geneva, where he and other diplomats are meeting on the crisis in Ukraine. "Just in the last couple of days, notices were sent to Jews in one city indicating that they have to identify themselves as Jews," he said. "In the year 2014, after all of the miles traveled and all of the journey of history, this is not just intolerable -- it's grotesque. It is beyond unacceptable." Kerry said if anyone engages in these kinds of activities on either side, "there is no place for that." Photographs of the leaflets have been circulated by multiple media outlets. It remains unclear whether a formal or informal government body is really behind them. An Israeli official told Fox News that the issue was brought to the attention of the Israeli embassy and foreign ministry, though they presume the leaflets were handed out by local militia members as a kind of provocation. The official also said the notices were distributed by masked men. State Department spokeswoman Marie Harf said U.S. officials are trying to gather more information.