TORONTO — Canada's Supreme Court ruled on Friday that a ­Vancouver-based mining firm can be sued in a Canadian court for alleged complicity in human rights abuses overseas — a decision that could alter the way businesses here assess the risks of operating abroad.

Canadian courts have been hesitant to consider such cases, opting instead to punt them to the jurisdictions where the violations were alleged to have occurred. The case brought by three Eritrean refugees against Nevsun Resources was closely watched, particularly by Canada’s extractive sector.

The Eritreans claim that Nevsun breached international laws against forced labor, slavery and crimes against humanity at its Bisha mine in the East African country.

They say they were conscripted indefinitely through Eritrea’s military service to provide forced labor at the gold, copper and zinc mine that is one of the largest sources of revenue for that country’s economy.

The say they were forced to work 12-hour days in scorching temperatures and beaten for taking breaks. They say their punishments included being made to roll in hot sand and being beaten with sticks until they lost consciousness.

Canada’s top court was not asked to judge the case on its merits. Its job was to consider whether the case should proceed to trial at all, and whether breaches of customary international law, ordinarily applied to sovereign states, could be actionable as torts against companies.

Nevsun, which owns a 60 percent stake in the mine, denies the allegations. It argued that the case should be dismissed under the act-of-state doctrine, which holds that the courts of one country shouldn’t judge the lawfulness of the actions of another within its own borders.

In a split decision Friday, the Supreme Court said the doctrine doesn’t apply in Canada. The Eritreans may now seek damages at a British Columbia court.

“Since the customary international law norms raised by the Eritrean workers form part of the Canadian common law, and since Nevsun is a company bound by Canadian law,” Justice Rosalie Abella wrote for the majority, “the claims . . . should be allowed to proceed.”

International norms on human rights abuses are “not meant to be theoretical aspirations or legal luxuries,” Abella wrote, “but moral imperatives and legal necessities.”

Joe Fiorante, lead counsel for the Eritreans, called the ruling a “huge victory for our clients in their struggle against massive odds to vindicate their rights.”

Plaintiff Gize Araya said he was “overjoyed” that the court was “giving us a voice to tell our stories about what we suffered at the mine.”

A lawyer for Nevsun, which was acquired by a Chinese firm last year for $1.3 billion, did not respond to a request for comment.

Canada’s minerals sector contributed 5 percent — or $72 billion — to the country’s nominal gross domestic product in 2018.

The Mining Association of Canada warned that a decision to allow the case to proceed would put Canadian companies at a “competitive disadvantage.”

Luis Sarabia, a lawyer representing the industry group, said it was “too early to tell” what impact the decision could have on mining companies. He said there would probably be more clarity after the British Columbia court decides the case.

“The [Supreme Court] simply ruled that it was not ‘plain and obvious’ that the case could not succeed,” he said. “It was a very high threshold that Nevsun had, and Nevsun didn’t meet that threshold.”

In 2018, Prime Minister Justin Trudeau’s government created an independent watchdog to monitor and investigate claims of human rights abuses by domestic firms operating abroad. But the post sat vacant until May of last year.