WATCH: ‘Mutual combat’ on Portland bridge after caravan of Trump supporters almost ran over protesters

There were tense situations in Portland on Saturday as a caravan of Donald Trump supporters drove through the city.

"With the usual caveat that I'm terrible at crowd estimates, I'd say about 1,000 people are here throughout the parking lot right now and maybe like 1 million flags," is how New York Times correspondent Mike Baker described the event.

Oregon Public Broadcasting journalist Sergio Olmos posted videos of a truck almost running over protesters and "a lot of aggression."

He then posted videos of "mutual combat" -- followed by police making arrests: