A Canadian public inquiry concluded Thursday that authorities should have known an Air India flight in 1985 was a likely terrorist target.

TORONTO — A Canadian public inquiry concluded Thursday that authorities should have known an Air India flight in 1985 was a likely terrorist target.

The bombing of Air India Flight 182 killed 329 people in one of the world’s deadliest terrorist strikes. It is the largest case of mass murder in Canadian history.

Former Supreme Court Justice John Major said Thursday a cascading series of errors contributed to the failure of Canada’s police and security forces to prevent the bombing.

“The level of error, incompetence, and inattention which took place before the flight was sadly mirrored in many ways for many years, in how authorities, governments, and institutions dealt with the aftermath of the murder of so many innocents,” Major said in a five-volume report.

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The Air India flight from Montreal to London, originating in Vancouver, exploded and crashed off Ireland on June 23, 1985.

An hour earlier, a bomb in baggage intended for another Air India flight exploded in the Tokyo airport, killing two baggage handlers.

The attacks were blamed on Sikh militants based in British Columbia who, prosecutors said, sought revenge for a deadly 1984 raid by Indian forces on the Golden Temple in Amritsar, the holiest site of their religion. About 800 Sikhs, including militants taking refuge in the temple, died.

Before the bombings, Canadian intelligence officials had apparently learned of the plot by Sikh separatists in Canada and India to launch a terrorist attack.

“There were individuals in the Sikh community who claimed to have knowledge about the bombing and its perpetrators,” Major said.

The agencies failed “to offer adequate protection to those individuals,” he added. “Instead they engaged in turf wars.”

Inderit Singh Reyat, who was convicted of manslaughter in the bombings, remains the only suspect convicted of a role in the attacks. Two other accused were brought to trial, but never convicted.

Testimony from current and former members of the Royal Canadian Mounted Police and the Canadian Security Intelligence Service painted a picture of strained relations between the two agencies in the 1980s, with key wiretap tapes erased, leads left to grow cold, investigators quitting in frustration and crucial witnesses reluctant to cooperate because they feared for their lives.

Air-transport experts told of security lapses by Air India and Canadian airport authorities and regulators.

Major said holes in the country’s security systems still need to be fixed.

The inquiry did not have a mandate to identify the perpetrators of the crime; rather it was to determine what went wrong and what can be done to prevent a similar tragedy.

Major’s report also recommended compensation for the families which, he said, were often treated as adversaries.