Saskatoon police are investigating after what they suspect was a homemade explosive was detonated at the same building as the city’s provincial courthouse.

Emergency crews were called to the scene, at 19th Street East and Third Avenue South, just after 11 p.m. Wednesday.

The explosion prompted a heavy police response and left the entrance to Kilborn Place, which shares the building with the courthouse, visibly damaged.

Logan Tufts, owner of The Woods Ale House in downtown Saskatoon, witnessed the explosion.

“It really shook me. It was really loud,” he said.

Tufts was biking home and noticed a fire at the doors of Kilborn Place. He snapped a photo and tried calling 911, but the call dropped.

He then pulled over to a median at the intersection before trying the emergency call again. The fire was growing.

“It just got bigger and bigger,” he said.

He was looking down when the explosion occurred.

“When I looked up, the whole front of the door was gone,” said Tufts, who was able to reach 911 immediately after the explosion.

“It was pretty intense.”

No one was injured, according to police. No arrests have been made.

Investigators do not believe the explosion is tied to international terrorism.

“I want to make it abundantly clear at this time that we do not believe the incident is linked to any type of international terrorist activity,” Insp. Randy Huisman told media Thursday.

Saskatoon emergency crews have responded to several reports of suspicious packages across the city recently. Huisman said police do not have evidence to suggest the explosion is linked to any of the suspicious packages.

However, he said investigators are not ruling out any possible connection to an incident last month on the same block — the 200 block of 19th Street East — in which a backpack containing fireworks and Roman candles was left sitting on the ground.

“Both are still under investigation,” he said.

He provided no details on if police have any potential suspects. Numerous charges could be laid, he said when asked about potential charges.

Several units are investigating.

“This is a high priority for the Saskatoon Police Service,” Huisman said. “Post-blast explosive technicians, arson investigators, the general investigation section and canines trained in explosives detection have been used in this investigation so far.”

Security was upped and police were on scene at Saskatoon’s courthouses Thursday morning because of the explosion. Both courts remained in session.