The crowd of revellers that strolled, snacked, socialised and smoked their way through Hempfest in the northwestern US city of Seattle tallied approximately 75 000 people by sundown, according to organisers.

Many festival attendees wandered the downtown park smoking marijuana cigarettes in the summer heat.

Festival political in nature

Seattle police safeguarded the cannabis aficionados, not bothering to enforce local pot laws that make recreational marijuana smoking the city's lowest crime priority.

Hempfest is political in nature and protected by free-speech provisions of the federal Constitution, regardless of federal marijuana laws, concluded sergeant Lou Eagle, who headed the police detail at the event.

"We are there simply to protect a large group of people from others' misbehaving," Eagle told AFP. "We are not out there to enforce the marijuana laws."

Arrests at the 14-year-old annual event have been rare and, usually, didn't involve marijuana charges, Eagle said.

Police only arrest a pot smoker if they puff in a cop's face and ignore warnings to stop, Eagle said.

Marijuana laws condemned

Speakers condemned marijuana laws as unjust and urged support for reforms that would make cannabis legal in the United States.

They condemned a two-month-old US Supreme Court ruling that said federal laws making marijuana illegal trumped state laws legalising the drug for medical use.

"Now, we are talking about medical marijuana users dying in jail," said Hempfest speaking Douglas Hiatt, an attorney who said he often defends medical marijuana users.

US states such as Washington and California already treat recreational pot use as barely worth the attention of police or the courts.

"We have got to take back the power," said 46-year-old Hiatt. "It's an issue of democracy."

In the 12 states where local laws condone medical marijuana, it is commonly used to treat pain and appetite lose associated with cancer treatments and Aids.

Federal officials view marijuana as a dependency-producing drug lacking medical benefit and see Hempfest activists as disconnected from reality, according to Tom Rile of the Office of National Drug Control Policy.

"There's an urban myth the we are filling jails with low-level marijuana users," Riley told AFP. "Almost everyone in jail for pot is charged with trafficking in large amounts of marijuana."

Dominic Holden of the National Organisation for the Reform of Marijuana Laws defended Hempfest, calling it "an institution that has made talking about marijuana use socially acceptable in Seattle."

For the less-politically minded, the two-day event that started on Saturday was an opportunity to taste hemp-based baked goods and listen to live music.

Hempfest is billed by organisers as the largest marijuana legal reform event in the US.