Vancouver police are investigating whether an early morning arson fire at an East Vancouver duplex that was under construction is linked to a series of protests by individuals claiming to be members of an anti-gentrification group.

A group, calling themselves the Anti-Gentrification Front, claimed responsibility for burning down the building at Victoria and E. 1st early Wednesday morning and posted the claim on an anarchist online message board where other claims have also been made about attacks on banks and restaurants.

The incident comes in the wake of increased anti-gentrification activities, including vandalism, thefts and ongoing protests outside the new Pidgin restaurant in Vancouver’s Downtown Eastside.

Const. Brian Montague, a police spokesman, said investigators have not been able to verify the latest claim and are also looking at other possibilities, including disgruntled employees and unhappy squatters. But he said the seriousness of the fire, which nearly spread to an adjacent home, has raised the police department’s level of concern.

"Obviously this is a priority. Any time we get a serious incident like this we treat it as a priority when a group sees the need to rely on violence or arson to possibly make a point," he said.

The fire in the partly built duplex in the 1900-block of E. 1st Ave. was discovered by police around 1:30 a.m. and residents on either side were quickly evacuated. Vancouver firefighters got the fire quickly under control, but adjacent houses suffered minor damage.

Someone claiming to be from the Anti-Gentrification Front posted the claim anonymously on the anarchist message board anarchistnews.org, saying they had set fire to the building because they were "tired of seeing our lives and memories being torn down one development at a time.

"We wish and will create fear for developers in East Vancouver. The class war is heating up. We have no intention on stopping. If we, if you, allow this (to) continue you will be pushed out of East Vancouver due to rising rent and gentrification. If you are the cause of gentrification you should never feel safe."

A portable toilet on the construction site was spray-painted with an anarchist symbol and the warning: "We’ll be back."

Neighbours say the old house once had two apartments but the building had been abandoned for years.

Montague said police take the threats seriously.

"There’s someone who is claiming responsibility and we will be investigating whether those claims are true or not. But it is too early to tell right now if there is any validity to that right now," he said. "We will see if there is a link but there is nothing that we can say that links them right now."

Mayor Gregor Robertson issued a statement saying he was deeply concerned about the arson.

"The alleged arson of a house under construction is of significant concern to me, especially in light of extremist claims made online," he said.

"Innocent lives could have been lost. I would like to thank our first responders for their immediate action to evacuate the neighbouring homes. Violence of any kind will not be tolerated in the City of Vancouver, and any criminal acts will be investigated and responded to with every resource at our disposal."

For several years, predating the Vancouver 2010 Winter Olympics, anti-poverty activists and so-called "Black Block" groups have waged a small and so far ineffective war of vandalism on banks and other groups they see as capitalist symbols.

The Royal Bank, CIBC, HSBC and others have had windows smashed, and in several cases Molotov Cocktails — gasoline-filled bottles — have been thrown.

Heckling demonstrators have held ongoing protests outside Pidgin restaurant to draw attention to gentrification of the area. One woman was recently arrested and charged with a violent protest outside the restaurant after she tried to lock employees inside.

Individuals claiming to be part of an anti-gentrification movement also claimed responsibility for smashing the windows of a Commercial Drive pizzeria at least three times and stealing the sign from in front of Save On Meats on Hastings Street. Anti-poverty activists in the Downtown Eastside have repeatedly distanced themselves from the Anti-Gentrification Front.

This latest online claim has drawn comments from people — including some who call themselves anarchists — who said the arson fire wasn’t an anarchist action, especially considering it put people in neighbouring homes at risk.

At the height of the blaze, firefighters went door to door urging nearby residents to evacuate. Leslie MacDonald, who lives four doors away, had to flee with her cat and three dogs.

She "and the rest of the neighbourhood" waited on the corner for an hour until they were told it was safe to return home.

Despite the scare, MacDonald said she has "mixed feelings" about the stunt. "This is not the way to approach societal problems. It’s disturbing to think of that level of destruction, and the houses right next door with families and kids sleeping in them."

Still, she "understands the frustration with how expensive it is to live in Vancouver ... when there’s a divide like that there’s the potential for more action."

According to property records, the site had the same owner from 1996 to 2012, when it was sold for $671,000 to two property development companies.