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

The so-called 4-20 event held every year on April 20 is the "high holiday" for marijuana advocates, and smoke-ins were held from Toronto to Victoria and several points in between.

In Vancouver, the party/protest got started early and by noon there were about 2,000 people gathered in front of the city's art gallery.

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

In one corner of the square, two men hung a sign that read "No Prison for Pot," and in the other a banner urged protest-goers to "Free Marijuana."

"We hot-box the outside. A huge cloud goes up. It's great," said Justin Thatcher, who has attended the event for five years running and was manning a booth for Cannibis Culture magazine.

In hot-boxing, tokers huddle together to take advantage of second-hand smoke.

The pro-marijuana gatherings have been held across Canada and around the world each year for a decade now. Last year, more than a thousand people gathered on Parliament Hill, and an estimated 10,000 were on the steps of the Vancouver Art Gallery.

Federal Justice Minister Rob Nicholson took advantage of the unofficial holiday by holding a news conference to announce a tough-on-crime bill.

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."

"That's my advice to anybody here who's smoking up, that they should tell their supplier that when our government introduces a drug bill, they won't like it."

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

Pressed about why police were not making any arrests, Nicholson said he's not in the law enforcement business.

"You'll have to direct that to the officers in charge," he said.

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

A few officers could be seen skirting the crowd in Vancouver, keeping an eye as music and the smell of marijuana wafted through the crowd.

In the middle of the fray, Jesse Lobdell, 31, sat at a booth set up by the BC Civil Liberties Association, handing out pamphlets rather than pot.

The association has advocated decriminalization of marijuana for 40 years, said Lobdell. Things have changed considerably during that time, he pointed out.

"You can get 10,000 people on smoking pot on the steps of the art gallery," Lobdell said. "This is mainstream."

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.

Many waved flags that resembled the Canadian flag, with a marijuana leaf replacing the maple leaf in the centre.

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 if 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.

"We're not promoting people breaking laws and acts and statutes, we're not promoting that, but we have to be realistic when we're dealing with this many people," he said.

"We typically would be making those types of arrests but based on today's unique circumstances, our main focus is public safety."

In Edmonton, the air outside the Alberta legislature had a distinctive aroma as pro-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.

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

In Oakland, Calif., several hundred revellers lined up outside IGrow, a three-month-old cultivation equipment emporium. Security guards kept them at bay until 4:20 p.m.

IGrow has arranged to have a doctor working at the store three days a week to evaluate people seeking to become medical marijuana patients, and a handful of those at the 4-20 Eve party were able to snag last-minute appointments.

Allen St. Pierre, executive director of the National Organization for the Reform of Marijuana Laws in the U.S., said the drug's steady movement from counterculture indulgence to mainstream acceptance will be evident elsewhere in the United States on Tuesday, when four cable television channels have scheduled "a good chunk of programming to 4-20."

St. Pierre said that with the terms "marijuana" or "cannabis" regularly showing up on the top Internet searches and a measure to legalize the plant's recreational use appearing on as many as four state ballots in November, it's clear that groups like his, which has lobbied to decriminalize marijuana since 1970, are no longer blowing smoke."