Marijuana enthusiasts in Vancouver, above, and across the country celebrated an annual day of pot advocacy Tuesday. (CBC)

Pot advocates gathered across the country Tuesday and puffed en masse to protest the prohibition of marijuana.

Supporters of the legalization of marijuana celebrate the so-called 4-20 event every April 20, lighting up joints at 4:20 p.m. local time in various parts of the country.

This year, smoke-ins were held from Toronto to Victoria and several points in between.

Nobody seems certain about the origins of the 4-20 tradition, but the pro-marijuana gatherings have been held across Canada and around the world each year for a decade now.

In Vancouver, the party/protest got started early, and by noon, a few thousand people had gathered in front of the Georgia Street entrance of the city's art gallery.

Clouds of smoke rose over the conspicuously mellow crowd. Hash cookies were on offer at a cost of $5 for three, and an array of colourful pipes was displayed for sale.

In one corner of the public square outside the gallery, two men hung a sign that read "No Prison for Pot." Another banner urged Canadians to "Free Marijuana."

By the time 4:20 p.m. rolled around in Vancouver, marijuana enthusiasts were crammed shoulder-to-shoulder on the art gallery grounds. A steady stream of rain did little to discourage them.

Cheers and air horns could be heard as the master of ceremonies announced the magical moment had arrived, and by 4:21, a large cloud of smoke rose above the crowd.

Justice minister touts crime bill

Federal Justice Minister Rob Nicholson took advantage of the 4-20 event to announce a tough-on-crime bill at a news conference in Ottawa.

Only a few hundred metres away, on the lawn in front of Parliament's centre block, hundreds of youths openly smoked pot while police looked on with no apparent concern.

Nicholson was asked repeatedly about the point of maintaining a law prohibiting marijuana possession when it's so openly flouted and not enforced.

"We're not the party that will be decriminalizing this," he said. "We don't encourage this kind of activity, but we have zeroed in on our drug bill. It targets people who traffic, people who import, export drugs, manufacture, people in the grow-op business."

The bill Nicholson referred to was introduced in the last session, but died when Parliament was prorogued. It's expected to be reintroduced shortly.

Toronto arrest

Police, for the most part, turned a blind eye to the gatherings.

A few officers could be seen scouting the crowd in Vancouver.

In Toronto, hundreds of marijuana enthusiasts converged in downtown's Yonge-Dundas Square.

Police stood and watched as the generally happy bunch puffed on reefers, danced and played drums.

While the crowd was mostly peaceful, police arrested a man after he reportedly pulled out a gun. A spokesman said police are still trying to confirm whether the object seized was an actual firearm or a replica.

A "smoke-out" was also held in Winnipeg on the front lawn of the Manitoba legislature.

More than 2,000 people openly smoked up, while more than a dozen officers watched the crowd from a distance but made no arrests.

"Our main focus for the afternoon is the safety of everyone in attendance," said Const. Jason Michalyshen, spokesman for the Winnipeg Police Service.

In Edmonton, the air outside the Alberta legislature had a distinctive aroma as marijuana supporters met outside the building.

Premier Ed Stelmach said their music rattled the windows of his office and made it trying at times to work but that he wasn't tempted to join the crowd.

Similar 4-20 events were planned for Regina, Victoria, and Calgary, as well as Colorado, New Hampshire, New York and California and several other U.S. states.