Drumming, chanting and calls for justice could be heard eight floors up, where Commissioner Wally Oppal opened the Missing Women Inquiry.

Tuesday's rally blocked downtown Vancouver traffic, but it did not derail the inquiry, which many critics say is stacked heavily in favour of the police and authorities.

The Assembly of First Nations was the latest group to pull out of the hearings, demanding the provincial government suspend the inquiry until more money can be found to fund lawyers to ensure fair treatment.

"It's an absolute disgrace, a national disgrace," AFN National Chief Shawn Atleo said to shouts of "shame" from the demonstrators.

Union of B.C. Indian Chiefs Grand Chief Stewart Philip said it's unacceptable for the families of murdered women to finally get a full public inquiry but one that will not deliver the answers they need.

"We need to send a message upstairs and that message is 'Oppal resign,'" Philip said.

Almost every group that had been granted standing at the inquiry and recommended for legal funding by Oppal has now withdrawn after the province refused to provide more money.

Other prominent groups that left the process last week included Amnesty International and the B.C. Civil Liberties Association.

Publicly funded lawyers representing police will aggressively cross-examine vulnerable women who try to testify, the groups say. But only a tiny handful of opposing lawyers will press testifying officers for answers and sift through thousands of pages of documents that will be released.

Oppal vowed the inquiry will provide a level playing field.

The inquiry will probe how serial killer Robert Pickton was allowed to prey on drug-addicted women from the Downtown Eastside for so many years and what can be done to prevent anything similar from happening again.

It began with a minute of silence for the murdered women and a statement from Oppal that painted a human portrait of those who were killed.鈥‥ach woman was valued, had dreams, hopes and fears, he said.

They were daughters, granddaughters, sisters, nieces, wives, friends, and often mothers, Oppal said.

"Individually the loss of each women is heartbreaking," he said. "Taken together, the loss of so many women is horrific."

Oppal called the inquiry a chance to show our society values its most marginal community members.

Pickton was convicted on six counts of second-degree murder in 2007, although he claimed to have killed 49 women.

The sisters of one of his victims, Georgina Papin, travelled from southern Alberta to witness the start of the inquiry.

Elana Papin and Cynthia Cardinal said they hope the probe could lead to the arrests of "other predators" or accomplices of Pickton who they believe participated in the killings.

"We're here for Georgina," Cardinal said. "She's with us. We can feel her spirit around us. She had seven beautiful children and we're here for her children also."

Ernie Crey, the Chilliwack brother of murdered woman Dawn Crey, said he's not angry most groups are boycotting the hearings.

"We're disappointed though," Crey said, adding he believes the inquiry has the best chance of success if as many groups participate as possible.

Photo: National Chief Shawn Atleo of the AFN addresses rally