Ezzatollah Rashidian, Kurdistan’s border commander, told Mehr news agency three soldiers and a border guard officer died when the station in the town of Marivan was the target of a grenade attack on Friday night.
Five other border guards were injured in the attack for which no one has taken responsibility, according to the agency.
But Iran’s English language Press TV, quoting unnamed local sources on its website, accused the Party of Free Life of Kurdistan (PJAK), an Iranian Kurdish separatist group, of carrying out the attack.
Western Iran, which has a sizeable Kurdish minority, has seen deadly clashes in recent years between security forces and rebel groups operating from bases in neighbouring Iraq and Turkey.
In early March, gunmen killed four forest rangers in the province. And seperate attacks on March 25 saw two security forces killed in the city of Sanandaj, the provincial capital.