Portland police are scouring security video as they try to find out who is responsible for tire slashings and other vandalism at parking garages in the city.

Multiple cars have been damaged in the parking garage attached to the Casco Bay Lines terminal and in the Gateway garage on High Street, police said.

At least some of the damage was done Friday, and was discovered by owners as they returned to their cars in the afternoon.

Perry Sutherland returned from a vacation and found a flat tire on his Ford Ranger. He inflated the tire enough to get to a service station, but he ended up having to replace it.

“There was a perfect half- to three-quarter-inch slit that clearly was a puncture wound in the sidewall,” said Sutherland, who lives on Peaks Island and has been parking in the garage next to the ferry terminal since 1990. Other people have reported multiple tires slashed, he said.

“For me, it was only a $200 out-of-pocket expense. For some folks, it’s been 700 bucks,” he said. “Some of us can afford to replace a tire, but a lot of folks don’t have cash in pocket for this.”

Police received about a half-dozen reports of vandalism to cars in each of the two parking garages, but Sutherland said it appears many more cars were affected.

Steve Kalisz, general manager of MHR Management, which oversees the garage next to Casco Bay Lines on the Maine State Pier, said the company is working with police to identify suspects. He is aware of eight or nine cars that have been vandalized at that garage but has had no problems at two other garages the company manages.

Kalisz said the damage appears to have been done Friday afternoon because his employees walked the garage early in the day and then learned of the damage about 4 p.m. Some victims reported damage to MHR Management and others filed reports with police, but there are people who say they can’t be bothered, he said.

Police are looking for any information about the vandalism, asking anyone who “saw something suspicious to contact us,” said Lt. James Sweatt, head of detectives for the city.

Sutherland said the episode has been the subject of much discussion among islanders who ride the ferry, and now when they disembark in Portland, they are relieved if they find all four of their tires inflated.