The smell of marijuana smoke wafted across several blocks of downtown Vancouver Wednesday as thousands gathered on the grounds outside the city's public art gallery for annual pro-pot rally.

Dubbed the "4-20" rally, similar gatherings are held every April 20th in cities around the world to promote the legalization and acceptance of marijuana. It culminates with a giant "smoke-in" at 4:20 p.m.

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Thousands of pot smokers openly smoked the banned substance in Vancouver Wednesday. ((CBC))

There was no obvious uniformed police presence as protest songs were played, many people openly smoked marijuana and speakers called for removal of pot-related offences from the Criminal Code.

Jodie Emery, wife of Vancouver's self-styled "Prince of Pot"  Marc Emery, was among those who addressed the crowd.

"When that clock hits 4:20, and we send up a big smoke signal to celebrate our freedom let us remember those we have lost and let us fight so we don't lose anyone else ever again," Emery said.

Her husband is serving a five-year prison sentence in the U.S. for selling marijuana seeds through the mail in that country.

The name "4-20" has many reputed origins but it's believed to have originated in the 1970s at a California high school where students would gather at 4:20 p.m. every weekday to smoke pot.