PORTLAND, Ore. (AP) -- Police seized weapons such as bear spray and shields as right-wing groups and counterprotesters gathered in downtown Portland, Oregon, on Saturday.
Authorities also set up concrete barriers and closed streets in an effort to contain the groups.
Flag-waving members of the Proud Boys and Three Percenters militia group began gathering late in the morning, some wearing body armor and helmets. Meanwhile black clad, helmet and face-mask wearing anti-fascist protesters were also among the several hundred people on the streets.
Polices said they had seized weapons such as metal and wooden poles, bear spray and shields from multiple groups that were gathering on both sides of the Willamette River, which runs through the city.
More than two dozen local, state and federal law enforcement agencies, including the FBI, were in the city for the right-wing rally that was expected to draw people from across the country.
Police said over a loudspeaker that people on the streets for the unpermitted rallies could be arrested.
The gathering was hyped on social media and elsewhere for weeks.
In the days leading up the event Portland Mayor Ted Wheeler said people who espoused hate or engaged in violence were "not welcome."
In a Saturday morning tweet, President Donald Trump wrote "Portland is being watched very closely." He also wrote that "major consideration is being given to naming ANTIFA an `ORGANIZATION of TERROR."'
But it wasn't immediately clear what he meant by that as there's no mechanism for the United States government to declare a domestic organization a terror group. The State Department maintains a list of designated foreign terrorist organizations, such as al Qaida, but there's no comparable designation or list for American groups.
Not all who gathered late Saturday were with right-wing groups or antifa. Also on hand were people who attended a nearby prayer service, holding signs that said things like "No Trump, No NRA."
Self-described anti-fascists -- known as antifa -- had vowed to confront the rally while leaders from the far right urged their followers to turn out in large numbers to protest the arrests of six members of right-wing groups in the run-up to the event.
Patriot Prayer's Joey Gibson, who is not involved in this weekend's event but organized similar rallies in 2017 and 2018 that erupted in clashes, surrendered Friday on an arrest warrant for felony rioting.
He was at a confrontation that broke out on May 1 outside a bar where antifa members had gathered after a May Day demonstration.
In a video he livestreamed on Facebook, Gibson accused the police of playing politics by arresting him but not the masked demonstrators who beat up conservative blogger Andy Ngo at a June 29 rally that drew national attention to this liberal city.
A video of that attack went viral and led the Proud Boys, who have been designated a hate group by the Southern Poverty Law Center, to organize Saturday's event.
"What I'm saying to everybody who's listening to this (is) they're trying to shut you guys up. They want you to not show up in Portland, they want to put fear in your hearts," Gibson said.
Portland Police Bureau spokeswoman Tina Jones declined to comment about specific arrests but said generally police continue to investigate several incidents from clashes on May 1 and June 29 and are politically neutral.
Antifa members often cover their faces with masks, making it harder to identify them.
"We receive criticism no matter what. It's either too much, not enough, you arrested this group and not this group," Jones said. "One hundred percent, it's about public safety."
In addition to the Proud Boys and Three Percenters, the white nationalist American Guard also said it would have members in Portland.
"It would be best for the patriot/conservative cause if this August 17 rally were simply canceled," the group's founder, Stewart Rhodes, wrote.
Authorities asked residents not to call 911 unless it's a life-threatening emergency and to stay away from the heart of downtown.