Iran executed two men on Saturday over an attack on a Shi'ite shrine that killed at least 13 people in October and was claimed by the militant group Islamic State, Iranian state media reported on Saturday.

The two were hanged at dawn in the southern city of Shiraz, the official news agency IRNA reported.

The men had said during their trial that they had been in contact with the Islamic State in neighbouring Afghanistan and helped organise the attack on the Shah Cheragh shrine in Shiraz, according to Iranian media reports.

CCTV footage broadcast on state TV showed an attacker entering the popular shrine after hiding an assault rifle in a bag and shooting as worshippers tried to flee and hide in corridors.

The gunman, identified as a citizen of Tajikistan, later died in a hospital from injuries sustained during the attack. Officials initially said 15 had been killed in the attack, but later revised the figure to 13.

Islamic State, which once posed a security threat across the Middle East, has claimed earlier violence in Iran, including deadly twin attacks in 2017 that targeted parliament and the tomb of the Islamic Republic's founder, Ayatollah Ruhollah Khomeini.