SASKATOON -- Police in Saskatoon are investigating the detonation of an improvised explosive device at the provincial courthouse.

Police say there have been no injuries but there are reports of minor damage to the exterior of the building.

They say the call came in just after 11 p.m. on Wednesday night.

Members of the Saskatoon police force's Explosive Disposal Unit are on scene as well as a bomb-detection-trained dog unit.

No arrests have been made.