In one of the attacks, a group of armed separatist terrorists raided a police station in the city of Zahedan on Friday afternoon, hurling Molotov cocktails at the facility and opening fire on people, according to local officials and police.
State TV said armed separatist terrorists had concealed themselves among worshippers at the nearby Makki Mosque.
Security forces quickly responded to the attack and restored order in the area.
As the terrorists failed in the attack, they engaged in acts of vandalism against banks, stores and public property elsewhere in the area, officials say.
The assault claimed the lives of 19 people and injured 20 others.
Meanwhile, terrorists also opened indiscriminate fire near Makki Mosque following Friday prayers.
Security forces swiftly arrived at the scene and ended the shooting attack.
Senior IRGC intelligence commander Seyyed Ali Mousavi was shot in the chest during an exchange of fire with the gunmen and transferred to a hospital. He later succumbed to his wounds.
The so-called Jaish al-Adl terrorist group claimed responsibility.
Iranian authorities said the elements behind the violence in Zahedan had been identified and arrested.
One of those arrested at the site, identified as Gorgij, recounted the circumstances surrounding the shooting attack.
He said a Peugeot 206 stopped near the police station prior to the attack and distributed arms among a group of people, including himself, who had gathered there.
The detainee said he took a sidearm but he tried to flee the scene as the terrorists started to shoot at the police station.
Sistan and Baluchestan Province borders Afghanistan and Pakistan, and has seen previous attacks on security forces by terrorists who infiltrate the country’s borders from the neighboring states.