Ukrainian forces seized more than 1,000 square kilometers of Russian territory in the Kursk region in a surprise offensive earlier this month.
Paton Walsh, CNN’s chief international security correspondent, reported from the Ukraine-controlled Russian town of Sudzha last week, according to a report and video published by the America media outlet.
Last week, the FSB also opened a criminal case against journalists Simone Traini and Stefania Battistini from Italian broadcaster RAI for crossing into Sudzha, it said.
POLITICO has contacted CNN for comment.