PORTLAND, Ore. - Following a spate of three vehicle fires early Tuesday morning, fire crews were again busy Wednesday morning with more vehicles set ablaze.

While the Tuesday fires all involved Honda CRVs, the fires Wednesday hit a random set of vehicles, only one of which was a Honda.

The first fire took place just after 4 a.m. near Southeast 74th and Otty Street in Clackamas. Owners of a Saturn Vue and Buick found both vehicles on fire in their driveway. No one was injured, but both vehicles were destroyed.

Police said it appeared that the Saturn Vue was set ablaze and the fire jumped to the Buick, which was parked next to it. Residents reported hearing a loud bang and then found the cars on fire.

About 30 minutes later, fire crews received reports of another vehicle on fire on Southeast 74th and Tolman Street. A Honda Element was destroyed at that location. No one was injured.

Just 20 minutes later, another report of a vehicle on fire came from the 5300 block of Southeast 96th Avenue. A Ford Ranger pickup truck was destroyed by fire at that location.

The fires were in the same general area as the three vehicle fires on Tuesday. Crime scene investigators are trying to determine if the fires are related.

"Obviously, we have someone who is very disturbed running around southeast Portland lighting cars on fire," said Lt. Allen Oswalt with the Portland Fire Bureau.  "Whether it's just a copycat or what, we have no idea yet."

A total of nine vehicles have now been destroyed or damaged by fire.

Investigators have set up a hotline - (503) 823-3791 - that people can call if they have tips on the incidents. Vehicle owners in southeast Portland are being advised to check their gas cap doors for evidence of someone trying to break them open, a sign of a failed attempt to set the vehicle on fire.