State media report that an attack at the Shah Cheragh mausoleum in the Iranian city of Shiraz has resulted in at least 15 deaths and ten injuries.
According to the Irna news agency, three armed men entered the shrine at 17:45 (14:15 GMT) and fired on pilgrims.
It also stated that police special forces had detained two of the attackers and were on the lookout for the third.
Officials were cited as saying they acted like “takfiri terrorists” – a reference to Sunni Muslim extremists.
Irna published photographs showing broken glass, prayer beads, and blood on the floor of the mausoleum.
The mausoleum includes the tombs of two sons of the seventh Shia Imam Musa al-Kadhim, who are also the brothers of the eighth Imam Ali al-Rida.