Attackers shot dead two members of Iran's Revolutionary Guards at their home in the western city of Paveh, near the border with Iraq's Kurdistan region, state media reported Tuesday.
It was not immediately clear who was behind the shooting, but Tehran has frequently blamed Kurdish separatist groups in the area for previous violence, accusing them of links to the United States and Israel.
The two IRGC members were killed in "a terrorist and cowardly act", state television said, while two other Guards members were wounded.
State television said "exact details of this incident and the measures being taken to identify those responsible are under review".
Separately, "a family's vehicle was sprayed with bullets" on Monday in the southeastern town of Saravan in Sistan-Baluchistan province, killing the father and wounding the mother, state television reported.
The woman later died of her injuries.
Authorities did not immediately identify those responsible or provide further details about the victims.
But state television said the attack "was carried out by Zionist-American mercenaries", a term Iranian officials commonly used for separatist and militant groups.
Sistan-Baluchistan, which borders Pakistan and Afghanistan, has long seen clashes between security forces, insurgents and drug smugglers.
One of Iran's poorest provinces, it is home to a sizeable ethnic Baloch population.
