At least 15 people were killed and ten others injured on Wednesday following an attack in the Shah Cheragh Shrine of Shiraz, Iranian state news agency IRNA said.
A media outlet affiliated to Iran's judiciary said three armed men had entered the shrine at 5:45pm local time (1415 GMT)located in Iran's southern city of Shiraz.
IRNA said the attackers acted as "Takfiri terrorists" - a reference to Sunni extremists such as Islamic State militants.
(Reporting by Dubai Newsroom; Editing by Toby Chopra)