Boston Celtics centers Enes Kanter and Tacko Fall were apparently threatened outside a Cambridge mosque Friday, Kanter said on Twitter, posting video of the encounter.Kanter says he, who was with Fall in the video, attended Friday prayer at the mosque off Prospect Street in Cambridge, but ran into an issue as they were leaving. The video shows one person, speaking in Turkish, while filming him outside of the mosque following the service. Kanter, a native of Turkey, has been estranged from his homeland for at least two years and is a longtime critic of Turkish President Recep Tayyip Erdogan."#DictatorErdogan thugs attacked and threatened me today after Friday prayer in Boston at a mosque," Kanter wrote on Twitter. "Turkish Government don't even let me practice my religion freely in America let alone my freedom of speech is under attack," he wrote.A spokesperson for Cambridge police said the department was aware of a video that was posted online, but a report was not immediately filed with the department. "Regardless, our investigations unit has been notified of the video," police said. The FBI told WCVB that they were aware of the incident. "We've been in contact with the Celtics, and we're going to decline further comment."In 2017, Kanter called Erdogan the "Hitler of our century. The Turkish government labeled Kanter a member of a terrorist organization. His passport was revoked and Turkey issued an extradition warrant for his arrest with Interpol.In December 2017, the Turkish state-run news agency said prosecutors sought a four-year sentence for Kanter for insulting Erdogan over Twitter in 2016. In May 2017, Kanter said he was detained in Romania after authorities told him his passport was invalid. He said that Turkey rescinded his passport because of his “political views.”Kanter missed a game in Toronto last season because he felt like his life might be in danger if he left the United States. Kanter said one of his basketball camps scheduled for the Islamic Center of Long Island this past summer was canceled earlier this summer due to "bully tactics" after the Turkish Consulate in New York City threatened the mosque.The Celtics and Kanter agreed to a two-year, $10 million deal in the offseason. Kanter previously played for the New York Knicks and Portland Trail Blazers.