Vietnamese Community in Australia vice-president Than Nguyen said the June 18 desecration of the Vietnam War monument and a World War II plaque signalled a need to increase security.

Red paint was poured on the memorial and set alight. A World War II plaque was also splashed with paint. The memorial was vandalised in 2006 and cost the council $316 to clean up, Mayor Nick Lalich said.

''This time the clean-up bill was $742,'' Mr Lalich said.

''This money would be better spent improving our city and not cleaning up heartless acts of vandalism.''

Council officers met with Vietnamese community members last Wednesday to discuss tighter security.

After consultation with the local Vietnamese community, council will install lights in the area in an effort to prevent further damage, Mr Lalich said.

''I urge the community to report any suspicious behaviour to the police,'' he said.