The Surrey Police Service (SPS) says it is investigating a suspicious fire at city hall in the early morning hours Monday.

Police say they responded to a report of the blaze from fire crews around 3:30 a.m. When officers arrived, they found the southwest side of the building engulfed in smoke.

Surrey Fire Services tells the SPS that the fire likely started in a portable toilet outside the building, which caused glass on the exterior to break due to heat. Interior sprinklers were triggered by the smoke that then entered through the windows, the fire department says.

Investigators say the blaze appears to have been human-caused and that they have obtained footage of a possible suspect seen in the area before the fire.

Police say the suspect is between 45 and 65 years old with short hair and a slim build. In the video, he appeared to be wearing a light-coloured ballcap, a dark shirt with a graphic on the front, dark shorts, and slides with light-coloured socks. He was wearing a red and white lanyard around his neck and a fanny pack.

The blaze resulted in significant damage to the property, but no injuries have been reported, the SPS says.

Police have released a photo of the subject and are asking anyone who recognizes him or who has more information about the fire to call the SPS non-emergency line at 604-599-0502 and refer to file 26-72511 (SP).