General Saeed Montazer al-Mahdi said terrorists attacked a police station in the city of Rask at midnight.
Some of the injured are in critical condition, officials say.
The deputy governor of the province Alireza Marhamati said a number of assailants were also killed in the attack at 2 am, local time.
Iran blamed the so-called Jaish al-Adl separatist group for the attack.
Iran says the seperatist teetor group is supported by the US and Israel.
The group has been behind several deadly bombings, ambushes and other attacks on Iranian security forces and civilians in the region, as well as abductions.
In one case, the terrorist group killed 27 members of Iran’s Islamic Revolution Guard Corps (IRGC) in a suicide bombing on a bus in 2019.
The so-called Jaish al-Adl operates from bases in neighbouring Pakistan.
