Council has been forced to spend upwards of $1000 repairing the damaged walkway of the Bridge.

"What a mindless and stupid act. It the most irresponsible act I've heard of in the last 10 years," he said.

"It's a highly valued icon, one of our heritage features and tourist attractions. To be lighting a fire in an attempt to make it inoperable is just appalling behaviour."

Queanbeyan Police were alerted to a small fire burning on the Bridge at about 6.50pm on last Saturday.

The fire was extinguished by the Queanbeyan Fire Brigade with damage sustained to part of the wooden walkway and timber below it.

"[The fire brigade] did not see or observe anybody at the time, however it appears there was some accelerant in a glass bottle used to start the fire," Queanbeyan Police Inspector Chris Varley said.

"Police attended, took some photos and collected some forensic evidence. The fire did not interfere with the structural soundness of the bridge which is still safe to cross."

The Bridge was closed for the past two days as council workers carried out repairs. A repair plank was placed above the damage during the interim.

Cr Overall said the Suspension Bridge vandalism was just one in a recent string of "disturbing incidents".

"In the last week we've had a series of disturbing incidents including a break and enter in the Indoor Sports Centre and attempted break and enter into the Riverbank Cafe," he said.

"Queanbeyan Police will be investigating all these incidents."

Anyone with any information can contact Crime Stoppers on 1800 333 000. Information can be provided anonymously.

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