Nearly 21 years since 331 people lost their lives in Air India's Kanishka bombing, Canada [Images] on Wednesday launched a judicial inquiry into the worst terror attack ever mounted from its soil, nearly two years after a court acquitted two Sikh separatists of charges in the case.

• The Kanishka bombing

Retired Supreme Court Judge John Major, who heads the inquiry, laid out a timetable and other mechanics for the probe in an opening statement after meeting privately with about 80 members of the families who lost loved ones.

They're hoping the inquiry will finally bring a sense of closure and help to ease their personal pain.

The relatives of the victims -- whose demand was fulfilled when Canada announced a judicial probe into the Montreal-London flight's crash over the Atlantic Ocean -- were present on Wednesday in Ottawa on the occasion.

The judicial inquiry was announced by Canadian Prime Minister Stephen Harper on May 1, after consulting the families, in the wake of the acquittal of two accused -- Ripudaman Singh Malik and Ajaib Singh Bagri -- in March 2005 of all charges related to the bombings after a 19 months of trial.

Major is expected to decide over the next two months who will get legal standing at his inquiry and how much public money will be spent to help defray their legal costs.

The first witnesses are expected to testify in September.

The retired judge has no power to retry 2005's verdict.

He will, however, investigate the widely publicised turf wars between the Canadian police and the Canadian Security Intelligence Service, which hampered the initial investigation, Canadian Press reported.

Major will also delve into broad issues of anti-terroist policy that remain relevant in the wake of the 9/11 attacks, including airline security and underground financing of terrorist groups.

Witness protection is also one of the topics to be considered by Major under his terms of reference.

He will also look into the question of whether a panel of three judges should preside over the high-profile terrorist trials rather than leaving them in the hands of one jurist.

It's not clear how much of the evidence will be heard in public since the judge's mandate calls for closed door hearings on any information that could endanger national security.

"The inquiry is not just about the Air India families," said Lata Prada whose husband and two teenage daughters perished when Air India Flight 182 went down off the coast of Ireland on June 23, 1985, adding, "the one thing that
could come out of this tragedy is lasting, systemic changes that would ensure such an act will never happen again."

Dave Hayer, a Liberal member of the British Columbia Legislature, said, "We want to make sure to send a message to all terrorists, regardless of where they are, who they are, that Canada is not a safe place for them."

He is the son of Tara Singh Hayer, a Vancouver-area community newspaper editor who fought a running battle against the Sikh extremist group suspected of the bombing.

The elder Hayer was murdered before he could testify at the trial of two men accused of masterminding the attack.

Other potential witnesses complained of intimidation.

In an interview, Justice Major had said the inquiry will have done its job, if it makes the victims' families -- many of whom immigrated from India -- feel like real Canadians.