The cafe operates next to Ararat Olympic Outdoor Pool in the Alexandra Gardens.

Police Sergeant Brett Robinson said the offenders had entered by climbing over the fence that surrounds much of the pool.

"Overnight, unknown offenders have climbed the side fence of the cafe and cut a hole in a plastic blind to enter the back causeway between the cafe and the toilets," he said.

READ MORE:

"They've done some damage to a number of items, including a bain-marie and some fridges.

"Then they set fire to a small bin. A display board has also been damaged by fire. There appears to be no damage to the actual structure, and entry wasn't gained to the actual cafe itself.

"We believe that it's juvenile offenders that we're looking for, possibly more than one."

A Country Fire Authority spokesperson said "a small fire in an alcove of the cafe," had been reported at 10:26pm, with the incident then listed as having "stopped" at 10:33pm.

Before firefighters arrived on scene, a passerby had filled a bin from one of the nearby public toilets with water and doused the fire.

Gardens Lake Cafe owner Maria Tsangas said on Saturday morning that the incident occurred ahead of a busy weekend.

"We've had to hire a bain-marie because today we have the swim carnival," she said.

"We've got the Ride to Remember on tomorrow, so this couldn't have happened at a worse time."

Despite the circumstances, Gardens Lake Cafe was still able to open Saturday morning and serve customers as normal.

Ms Tsangas said she was grateful to the passerby who helped extinguish the fire and the police for their handling of the matter.

People who witnessed anything suspicious in the area between 10pm-11pm are urged to contact Ararat Police Station by phoning 5355 1500.

While you're with us, you can now receive updates straight to your inbox from The Ararat Advertiser. To make sure you're up-to-date with all the news from across the Ararat shire, sign up here.