Iran says it executed 9 Islamic State group militants detained after 2018 attack

"This terrorist cell intended to infiltrate Iran and conduct simultaneous attacks in border and central cities," Mizan quoted Guards ground forces commander General Mohammad Pakpour as saying at the time.

Guards units, supported by intelligence officers, tracked the suspects down and captured them in a deadly exchange of fire in the western mountains in which three officers were killed.

"Some of the terrorists blew themselves up with suicide vests," Pakpour said. "Three of our forces were martyred during the operation."

Equipment seized included machine guns, grenades, thermal cameras and large stockpiles of ammunition.

Judicial officials said the men were charged with waging war against God -- a capital offence in Iran -- through armed rebellion, terrorism and illegal possession of military weapons.

"The defendants were given a fair trial with legal representation and were sentenced based on evidence, confessions and witness testimonies," Mizan said.

The Tehran Revolutionary Court handed down the death sentences, which were later upheld by the Supreme Court.

"The judiciary’s resolve to confront terrorism remains firm," Mizan said.

Shiite-dominated Iran is a major target for the Sunni extremists of IS. Iran regularly announces arrests of suspected IS members accused of plotting attacks.

On Sunday, police said they had detained 13 suspected members of the group in coordinated raids across four provinces.

Last month, Iran executed a man convicted of spying for Israel.

Iran is the world's second most prolific executioner after China, according to human rights groups including Amnesty International.