A statue commemorating the man who chose the site of South Australia's capital has been vandalised and tagged with the words "Death to Australia".
The words "No pride in genocide" were also written on the base of the Colonel William Light monument, on Montefiore Hill which overlooks Adelaide's CBD.
Colonel Light was a British-Malayan naval and army officer who was appointed surveyor-general of South Australia and who also designed the layout of the state's capital.
The tags appear to be related to the Black Lives Matter movement, which drew more than 5000 people into Adelaide's city centre earlier this month, calling for justice over the death of American man George Floyd and an end to Aboriginal deaths in custody.
However, historical references to Colonel Light's time in SA do not indicate any particular issues with the Indigenous community.
The Boer War Memorial, located outside Government House in the CBD, was also vandalised.
Premier Steven Marshall said existing monuments would not be taken down but more should be erected to commemorate Aboriginal men and woman.
"We have got one of the most important statues commemorating Aboriginal men and women's service to Australia on the Torrens Parade Ground," Mr Marshall said.
"We should be putting up more statues in SA commemorating the great achievements of Aboriginal men and women. We should not be desecrating other statues in our state."
Black Lives Matter Adelaide protest organiser Natasha Wanganeen said she did not support vandalism but wanted Colonel Light's statue removed.
"Why does Australia want to hold onto these things that are disheartening to Aboriginal people?," she said on ABC Radio on Thursday.
"If it is at this point where people are spraying stuff and defacing things, that is a clear message to me that they do not want (the statue) there either."
Deputy Lord Mayor Alexander Hyde said he condemned the "cowardly" and "nonsensical" attack on the monument.
"I'm not going to defend any other injustices that have taken place across Australia, but South Australia was founded as a free settlement and on the principle of protection for everyone, including Indigenous Australians," he said.
Statues around Australia and the world have been defaced amid Black Lives Matter protests, with the statue of Townsville's Robert Towns, one of the Queensland city's founders, on Monday being defaced with red paint.