DUBAI (Reuters) - A Revolutionary Court in Iran on Saturday began the trial of a group accused of involvement in attacks last year which killed 18 people in the first deadly operation by Islamic State in the country.

Eight of the 26 suspects in the case attended the hearing, facing charges including belonging to a terrorist organization, weapons smuggling and unauthorized entry to Iran, the Iranian judiciary’s news website Mizanonline reported.

Sunni Islamic State, in decline in Iraq and Syria, claimed responsibility for the unprecedented attacks in majority Shi’ite Iran, in which suicide bombers and gunmen attacked the parliament and Ayatollah Ruhollah Khomeini’s mausoleum in Tehran. The attackers were Kurdish Iranian Sunnis.

Iran has said that the five gunmen and suicide bombers who were killed had fought in the militants’ strongholds in Syria and Iraq.