BERKELEY (BCN)-- Police said they have arrested twenty people and expect to arrest more today in connection with a protest between pro- and anti-Trump supporters in Berkeley.
Eleven people were injured and seven were taken to hospitals, officials say.
As of 1:48 p.m on Saturday., 15 people had been arrested in connection with the protest, which started this morning at Martin Luther King Jr. Civic Center Park at 2151 Martin Luther King Jr. Way.
Some type of gas was released this morning into a crowd of protesters in Berkeley's Martin Luther King Jr. Civic Center Park, a police spokesman said.
The protest between Trump and anti-Trump supporters is located near downtown Berkeley at 2151 Martin Luther King Jr. Way.
Spokesman Officer Byron White wasn't sure when protesters started gathering but some were going to gather at 10 a.m. and others at noon.
Officers encountered items at the protest that are prohibited such as flagpoles, a knife, a stun gun, helmets and signs and flags attached to poles.
Similar rallies in Berkeley on March 4 sparked melees that resulted in several people being injured and 10 people being arrested, although the Alameda County District Attorney's Office hasn't filed charges against anyone so far.
The city of Berkeley has issued a news release advising residents about how they can stay safe during the rallies if they attend them.
City officials said, "If you are at a demonstration and you see violence, separate yourself. Keep a distance. If you can do so safely, report it to police."
They said, "This is the best way to keep yourself and others safe, and it allows police to intervene safely. When individuals commit violence surrounded by a peaceful crowd, police are always concerned about how the
violence might spill over onto those who are not committing any crime whatsoever."
Berkeley officials said, "Separating yourself from violence also prevents those individuals from making their actions the image of your
They also advised, "Don't get baited by provocateurs."
City officials said, "Language used to announce a protest may be effective at enticing supporters, luring counter-demonstrators or provoking conflict. But, if you don't know the person, groups or source personally, use caution."
They said, "This is especially the case when groups do not use permits - a tool that indicates focus, organization and lawfulness. It's a tool that no one has sought for Saturday."
City officials said, "Mass gatherings of any kind attract a broad variety of people and, inevitably, that means an array of different motives and intentions. The overwhelming majority come with a peaceful purpose."
But the statement added, "However, in recent protests in Berkeley, we have seen a small portion who come seeking to hurt others or to destroy property. We have seen that individuals who come armed and armored use
peaceful protesters as a cover for their violent actions."
Berkeley officials said 9 of the 10 people who were arrested at the March 4 rallies came from outside the city.
Berkeley officials said the city and its police department "will continue to develop our strategies to ensure safety for all at demonstrations, each of which has its own unique dynamics."
"Our mission for Saturday is to safeguard our community while facilitating the expression of the First Amendment. We will work to identify, investigate, arrest and prosecute anyone who commits crimes in our community.
That won't end when the event does," the statement said.
The City of Berkeley website has posted designated rules to allow peaceful expression of free speech at Civic Center Park on Saturday. You can see it here.
Raw footage from the March 4 protests that erupted in violence: