Melbourne 'boll-art' backed by Vic premier

Concrete bollards installed to protect Victorians from vehicle attacks are being transformed into works of art and the state's premier has awarded them five stars.

The three tonne concrete blocks were installed on June 10 and have since attracted artists turning them into "boll-art" by covering them in colourful fabric, knitted covers and tongue-in-cheek jokes.

"I think it's great," Premier Daniel Andrews told reporters on Tuesday.

"You would expect nothing less in the cultural capital of our nation."

The opposition has questioned the placement of some of the blocks, with some far enough apart to potentially allow cars through.

"We take our advice from Victoria Police not the Victorian Liberal Party and it is totally irresponsible for people who really are not experts in these matters to be running a commentary," Mr Andrews said.

The bollards have been installed at key locations around Melbourne including Federation Square, Southern Cross station and the Bourke St Mall to prevent unauthorised vehicles entering.

Six people died and dozens of others were injured when a car drove through the mall in January.