Australian authorities said on Thursday they were treating as a terrorism incident an attempt to bomb a rally protesting against the country’s national day on January 26, the first such charge in the state of Western Australia.

They arrested a 31-year-old man on accusations of hurling a homemade bomb into a crowd of several thousand people in the city of Perth. No one was injured because the bomb did not explode.

Police and state leader Roger Cook said the man held white supremacist views and the attack was an attempt to target Aboriginal people, one of Australia’s two main Indigenous groups.

“This charge ... alleges the attack on Aboriginal people and other peaceful protesters was motivated by hateful, racist ideology,” Cook told a news conference. If proved, it carries a maximum sentence of life in prison.

Australia Day, which commemorates Britain’s colonisation of the country in 1788, is a public holiday marked by picnics, barbecues and ceremonies for new citizens but it has also attracted criticism from some, including in the Indigenous community, with “Invasion Day” protest rallies nationwide.

Polling shows a majority of Australians oppose moving the date of the holiday.