An Iranian court has handed out death sentences to two men over an attack on a Shiite shrine in Iran that killed 15 people in October and was claimed by the militant group Islamic State.

Fars Province judiciary head Kazem Mousavi said the two men had been found guilty of charges including "spreading corruption on earth" and acting against national security, the official news agency IRNA reported, adding that the sentences can be appealed.

CCTV footage broadcast on state TV showed the attacker entering the popular Shah Cheragh shrine in the southern city of Shiraz 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.

The two men sentenced to death said during the trial that they had been in contact with the Islamic State in neighboring Afghanistan and helped organize the attack, Iranian media reported.

Three other men received jail sentences ranging from five to 25 years in the trial, Mousavi said, adding that several other "Daesh (Islamic State) suspects linked to this case" were awaiting trial.

ISIS took responsibility for the attack on the Shahcheragh in Shiraz on October 26, but some questioned the Islamic Republic’s account saying it was staged by the regime itself to distract attention from nationwide protests.

With reporting by Reuters