TWO West Australian men alleged to belong to an extreme nationalist group have been arrested and charged with firing shots at a Perth mosque.

Three shots were fired into the dome roof of the Canning Mosque, also known as the Suleymaniye Mosque, in the southeastern suburb of Queens Park, in the early hours of Thursday, February 4.

Today, WA police raided two houses at Kalamunda and High Wycombe in Perth's east and a house in Bunbury in the state's southwest.

The two accused are alleged to be members of the Perth-based extremist group Combat 18, police said.

A 24-year-old High Wycombe man and a 25-year-old Greenmount man were charged with one count each of causing criminal damage, discharging a firearm across a road and possessing an unlicensed firearm.

A 19-year-old old Kalamunda man was charged with one count of possessing an unlicensed firearm.

A police spokeswoman said extremist groups or individuals who engaged in acts such as the mosque shooting would not be tolerated.

She said all available police resources would be used to investigate and prosecute such offences.