SYDNEY, Australia — Shouting “shame,” protesters on Monday held demonstrations across Australia to express their anger over what they said was a lenient sentence in the death of a 14-year-old Aboriginal boy.

Outside the Supreme Court of New South Wales in Sydney, many protesters wore black, yellow and red — the colors of the Aboriginal flag — and Black Lives Matter shirts. They said the sentence was yet another injustice against their community.

“Aboriginal blood has been spilled, and it continues to be spilled,” Lynda-June Coe, a representative of Fighting in Solidarity Towards Treaties, an advocacy group for Australia’s First Nations people, told the crowd. “The primary target of this undeclared war is our children.”

“When does this insanity stop?” she added.

The teenager, Elijah Doughty, was killed in August of last year in Kalgoorlie, a city in Western Australia, when a man, whose identity has not been released, ran him over in a truck. The man said that Elijah was riding a motorcycle that had been stolen from his house. The man said that he had been catching up to the motorcycle when it veered unexpectedly in front of his truck, leading to a collision.