A vigilante riot on New Brunswick's Grand Manan Island shows Canadians want their government to crack down on crime, says Prime Minister Stephen Harper.

"This is probably an extreme example of the desire of the population to see change and see crime fought in this country," Harper told the New Brunswick Telegraph-Journal during a stop at Hopewell Rocks near Moncton, N.B.

The prime minister was in New Brunswick to announce the renewal of a $20-million fund to help boost tourism in the Atlantic provinces.

Harper referred to the Grand Manan incident four days after a group of about 40 residents burnt a house to the ground in the community of Castalia and beat up the occupants.

Riot sparked by rumours of drug-dealing

The riot was attributed to a group of vigilantes who were responding to reports that drugs were being sold in the house. They allegedly marched on the house carrying guns, knives and baseball bats.

Several shots were fired at a car but the driver was not hurt. Four male residents of the home were badly beaten, and a woman was escorted off the island for her own safety. Several other people suffered minor injuries.

Police say they continue to investigate the riot and arson, but have yet to lay charges. One occupant of the burnt house has been charged in relation to an earlier incident.

Grand Manan is a quiet fishing community near the Maine border in the Bay of Fundy.

But local officials have warned of a growing drug problem, with crack cocaine becoming increasingly available. Prescription painkillers Dilaudid and OxyContin as well as ecstasy have also been noted in the community.

Harper said Wednesday his government is concerned about how the criminal justice system deals with serious crimes such as drug dealing.

Stiffer sentences needed: Harper

"Our government obviously shares residents' concerns that the laws are too lax," he told the Saint John newspaper. "Gun, gang and drug violence is not just in large cities."

The prime minister said his government plans to introduce minimum sentences for serious crimes and end conditional sentences for such crimes.

"I would urge the parties of the opposition to work with us to ensure that these laws are changed so that our police forces have the tools necessary to get the bad guys and put them behind bars," he said.

N.B. Premier Bernard Lord said the provincial government is also investigating the Grand Manan riot.

"It was a bad situation from what I can understand," said Lord, who is in St. John's for the premiers conference.

"I haven't had a chance to speak to the mayor and I don't have first-hand knowledge of what took place, but I've asked our ministers to look into that situation. I believe it's essential for governments to maintain law and order," Lord said.

"It's one of the reasons why we have governments and it's one of the reasons why we've added funding for RCMP and more officers in the province of New Brunswick."