WATCH: SD city attorney candidate mobbed by cops at Trump protest as candidate calls protesters 'thugs'
San Diego city attorney candidate Michael Pease is mobbed by police -- Twitter screenshot

Protests against presumptive GOP presidential nominee Donald Trump turned ugly Friday night as police arrested 35 demonstrators, including a candidate for city attorney who was filming an advancing phalanx of riot gear-clad policemen.

According to the San Diego Union-Tribune, Police Chief Shelley Zimmerman declared an unlawful assembly outside the San Diego Convention Center at 4:40 pm after supporters and opponents of the Trump clashed in the surrounding streets.

"We came in very quickly and decisively,"  Zimmerman said at a briefing after they streets were cleared. "The last thing we want is a mob mentality."

Zimmerman's "mob" comments were also reflected by Trump in a tweet following his appearance, when he wrote: "@SanDiegoPD- Fantastic job on handling the thugs who tried to disrupt our very peaceful and well attended rally. Greatly appreciated!"

Among those swept up by police was local lawyer Bryan Pease who is running for San Diego city attorney in the upcoming election.

In video uploaded to Twitter by NBC10's Michael Chen, Pease can be seen walking backwards and filming an approaching wall of police officers brandishing nightsticks when three officers break from the pack and wrestle the unresisting attorney to the ground before taking him into custody.

Early Saturday morning, Pease linked to the video on Twitter and announced that he had been released after spending ten hours in jail.

"Thanks for all the well wishes--I just got out of jail after 10 hours taken to process $500 bail I had on me!" he wrote.

Video of the arrest and tweets below: