Monuments for the Korean War and Vietnam War on Anzac Parade in Canberra have been targeted by pro-Palestine graffiti.
The graffiti was discovered on Sunday morning and police were notified.
It was the third time since March that memorials in this area have been targeted.
The Vietnam War monument was targeted in March and the Australian War Memorial was sprayed with graffiti two weeks ago.
Opposition defence spokesman Andrew Hastie said in a video on social media the protesters had "defaced the memorials and dishonoured our war dead".
"These people don't want to create a cohesive Australia. They want to tear down our institutions and divide us," Mr Hastie said.
The Military History Society of NSW said in a statement on Facebook the incident was "inexcusable".
"As a historical society we strongly condemn the desecration of war memorials and other public monuments," the organisation said.
"We again advocate more substantial penalties for the culprits."
ACT Policing is considering this incident along with graffiti that was sprayed on the Australian War Memorial on June 14.
A search warrant was executed on Friday, however, no charges have been laid.
People with information were urged to contact Crime Stoppers.
