Waterloo Regional Police say a suspected improvised explosive device appears to have been the cause of a vehicle explosion in front of a Kitchener courthouse on Friday morning that killed one man.

Emergency crews were called to Frederick and Duke streets around 10:30 a.m. for reports of a car fire.

Mike Sylvester, who was working at a nearby construction site, told CTV News Kitchener that his coworkers ran to the scene and saw a body inside the vehicle.

"It was engulfed in flames so they couldn't do anything," he said.

Around 2 p.m., police confirmed that a man was pronounced dead on the scene.

Several surrounding streets were evacuated following the explosion, and police are urging residents to avoid the area.

Police are conducting searches in two homes they believe are connected to the man.

"There continues to be an elevated concern for safety until we conclude our investigation and confirm that the residences of concern are safe and secure," said Superintendent Eugene Fenton.

"I can't speak to who created it, but it appears that the male who is deceased is responsible for this explosion."

Peel police's explosives disposal unit is assisting in the search.

- with files from CTV News Kitchener