Yesterday's operations included raids in the capital Skopje and northwestern Tetovo, in which computers, mobile phones and passports were seized, said police official Dejana Nedeljkovic.
"The police have arrested four Islamic State members who fought in Syria and Iraq," she said, adding that of the three others being searched, two were probably still fighting on the frontline.
According to the Macedonian police, about 130 nationals have left to fight for the jihadist group in Iraq and Syria.
According to Macedonia's criminal code, joining conflicts abroad as well as recruiting citizens to fight in foreign conflicts is punishable by five years in jail.
Macedonian President Gjorge Ivanov has said that 72 people who have returned from Syria to Macedonia are considered "potential terrorists".
Syria's war began in 2011 as a popular revolt seeking democratic reform, but later morphed into a brutal civil war that attracted jihadists from all over the world.