UPDATED 6 p.m.

Protesters from an Extinction Rebellion PDX rally used a fire truck to block Southwest Fourth Avenue near City Hall for several hours Friday afternoon.

The fire truck was purchased through Craigslist last week after supporters chipped in to raise the money, according to Ken Ward, a protest organizer with Extinction Rebellion. It represents wildfires, the biggest threat from climate change in this area, he said.

Around 200 hundred protesters chanted, “We the people declare a climate emergency," at the protest in Terry Schrunk Plaza, which is across from City Hall.

The rally began at noon. Its goal, according to a news release sent out by Extinction Rebellion PDX, was “to declare a ‘climate emergency’ and call for mass disruption of business-as-usual, as a last ditch effort to force action on the climate change crisis.”

Ward said the protesters planned to be there “until the climate emergency is dealt with,” and planned to have performers join the protest at a later point.

The Portland Police Bureau said Friday that the rally did not have a permit.

“We are weighing the risks/benefits of the road impact and the protester and public safety,” Tina Jones, a spokesperson for the bureau said over email Friday.

By 1:23 p.m., a lockdown was declared at City Hall in response to the protest.

Dorothy Elmore, the security manager at City Hall, confirmed the building remained on lockdown Friday afternoon. No one was being let in, even for official appointments. A mayoral aide said they had to move a meeting to a nearby building because their guest was not allowed in.

Shortly after 5:30 p.m., the event was over. “SW 4th Avenue in front of City Hall has been re-opened,” Portland police tweeted. “Demonstrators have moved on and dispersed.”

The apparently threatening situation — protesters singing, blowing bubbles and holding signs — has led someone inside City Hall to declare a lockdown. — Gordon Friedman (@gordonrfriedman) June 21, 2019

Protesters have taken over 4th ave between Jefferson and Madison in front of City Hall, demanding action on climate change. pic.twitter.com/tfk5cXc6Sm — Dave Killen (@killendave) June 21, 2019

Michael Esposito, director of green housing company Nuearth Biotecture, said his goal in attending the protest was “furthering the movement, getting more people to speak up and show up and figuring out some better answers.”

“People have been asking politely for decades for government to do something about this approaching crisis, with nothing but zip to show for it," Sarah Carlberg, an organizer with Extinction Rebellion PDX, said in the release. "But we can do the same thing here in Portland that people did on the streets in London, and we know that was phenomenal!”

Dave Killen, Diana Kruzman and Gordon Friedman contributed to this report.