SASKATOON -- It was a busy weekend for the Saskatoon Fire Department (SFD) as crews worked to extinguish blazes at three houses, all set deliberately, according to the department.

Firefighters responded to the first fire around 11:29 p.m. Saturday in the 400 block of 4rd Avenue North which resulted in damages around $250,000 and was incendiary.

Just after 3 a.m. Sunday crews responded to a call in the 300 block of Avenue U South. They arrived to a fire from the exterior of the home, and heavy smoke. There were no occupants or pets in the house.

A fire investigator determined the fire to be incendiary, with damage estimated around $100,000.

The fire department responded to a call for another fire shortly after 4 p.m. They arrived in the 1200 block of Avenue F North to find a detached garage on fire, and quickly extinguished it. There were no injuries to report.

Damage is estimated at about $5000 and also was incendiary.

Saskatoon Fire Department Assistant Chief Wayne Rodger said they are investigating these three fires as well as a fourth fire from July 16 at a boarded up house in the 1600 block of Avenue C North.

According to Rodger, the city has seen double the amount of intentionally set fires than seen last year at this time.

"Last year there were 29 incendiary fires by the end of July. Already by mid-July this year we’re at 58," Rodger said.

The department reminds the public to call the non-emergency line at 306-975-8300 or the police to report suspicious activity.

"Be wary of suspicious activity in your neighbourhood. If you see anything that doesn’t look proper, if you see somebody that you think doesn’t belong, phone the police," Rodger said.

No one was hurt at any of the fires, the department said.