The suspects were plotting an attack in several public places in the city of Saint Petersburg, which will host different football teams playing World Cup matches, reported Moroccan daily Assabah.
The suspects were in contact through social media, planning serious criminal attacks in the country. They were also plotting a suicide bombing in Kazan Cathedral in the center of the city.
During the criminal arrests, Russian police found explosives, guns, and molotov cocktails.
The report added that the Russian police is increasing its security services ahead of the 2018 World Cup in order to curb any attempted terrorist attacks.
The city of St. Petersburg is set to host several international teams, including Morocco, Argentina, Iran, Brazil, Russia, Egypt, and Costa Rica.