Iran’s Islamic Revolution Guards Corps (IRGC) clashed with Islamic State militants in the western part of the country on Saturday, according to Sepah News, the official news site of the Guards.
IRGC claims a team of 21 Islamic State fighters crossed Iran's western border and were placed under surveillance before the Guards attacked them on Saturday morning in Karmanshah province.
Most of the militants have been arrested, the report said, but there was no mention of the number of people killed or wounded in the clash.
The IRGC did not say exactly where the clash took place and provided no other details or any evidence of the military operation.
The Islamic Republic has made similar claims numerous times before but the IS group has never taken responsibility or confirmed any incursion into Iran.
Last June, Islamic State attacked the Iranian parliament in Tehran and the mausoleum of the Islamic Republic’s founder Ayatollah Ruhollah Khomeini, killing at least 18 and wounding dozens.
Iran’s Revolutionary Guards fired several missiles at Islamic State bases in Syria on June 18 in response to that attack.