
At least 21 people have been arrested after violence broke out Saturday between groups of Trump supporters and detractors holding rallies in downtown Berkeley, according to police.

Hundreds of people with opposing opinions on President Donald Trump threw stones, lit fires, tossed explosives and tear gas and attacked each other with makeshift weapons as police stood by.

Violence escalated when counter-protesters against a pro-Trump 'Patriots Day' rally broke through netting separating the two groups in Berkeley's Martin Luther King Jr Civic Center Park.

This is the third time that violent confrontations have broken out on the city's streets in recent months.

Supporters of the president attended a 'Patriots Day' rally, which was organized by the Liberty Revival Alliance, potentially as a counterpoint to Tax Marches being held in cities across the country.

About 250 police officers were deployed on Saturday afternoon as violence broke out among more than 200 protesters. Officials in Berkeley sought assistance from the nearby Oakland Police Department, according to the Los Angeles Times.

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A Donald Trump supporter breaks up a scuffle during the Patriots Day Free Speech Rally in Berkeley, California as counter-protesters broke through netting separating the two groups in a park

Trump supporters face off against protesters with smoke from a smoke bomb at Milvia St. and Center St. in Berkeley

An aerial view of the chaos in Berkeley shows how demonstrators left Martin Luther King Jr. Civic Center Park, where the fighting began, and walked along Berkeley streets closely followed by police

A Trump supporter bleeds after being hit by a counter protester. Dozens of police officers in riot gear were standing nearby

An anti-Trump protester flees from an oncoming charge of Trump supporters on Center St. in Berkeley Saturday afternoon

A police officer detains a pro-Trump demonstrator as groups of Trump supporters and detractors clash in Berkeley, California

Pepper spray was used by both sides of the clash which broke out early Saturday and continued through the afternoon

A Trump supporter wrapped in a Trump flag and a shirt that says he is a proud supporter of the Muslim ban looks on as fights break out

When the violence erupted in Berkeley they were quickly able to arrest one man (not pictured), and soon others were arrested as several fistfights broke out

Tens of thousands of people in 150 cities across the country marched on Saturday to demand that President Donald Trump release his tax returns and to dispute his claim that the public does not care about the issue.

His predecessors in the White House going back more than 40 years had done so.

One of the spots they are demonstrating is right on the doorstep of Trump's Mar-a-Lago resort in Palm Beach, Florida, where he is spending a long Easter weekend.

The marches across the country coincide with the traditional April 15 deadline for U.S. federal tax returns, though the filing date was pushed backed two days this year.

There were no reports of violence or arrests at any of these protests, which contrasts with the clash between Trump supporters and opponents that erupted at the rally in Berkeley, where police officers in riot gear stood by.

When the violence erupted in Berkeley they were quickly able to arrest one man, and soon others were arrested as several fistfights broke out. Some of those arrested were on suspicion of a deadly weapon, according to Officer Byron White of the Berkeley Police Department and the LA Times.

Both sides threw explosives and sprayed tear gas at each other, and a number of people had to have milk poured into their eyes after being affected by the gas.

Trump supporters charge against anti-Trump protestors amid smoke from a smoke bomb that was thrown into the crowd

A Trump supporter gets creative when he throws spoonfuls of scalding beans towards protesters rallying against the president

Fist fights broke out among members of both groups on the streets around Martin Luther King Jr. Civic Center Park, where pro-Trump supporters had scheduled a rally. Fireworks and smoke bombs were thrown into the crowd, and a few demonstrators were doused with pepper spray

A bloodied demonstrator is seen after a brawl broke out between conservatives and demonstrators in opposition to U.S. President Donald Trump

One of the anti-Trump demonstrators was detained by police officers in Berkeley as fights broke out around her

An anti-Trump demonstrator wears all black and burns an American flag handkerchief during the protest in Berkeley

A conservative demonstrator peacefully chants toward a group of counter-demonstrators during the rally

A man takes a hit in the back with a pole which was being used as a makeshift weapon after actual weapons were banned from entering the area

An anti-Trump protester is seen being pulled from one of many fistfights that had broken out between the two protesting groups

A woman gets milk poured in her eyes after getting sprayed with a chemical irritant, which was most likely tear gas

A Trump supporter (L) who is wearing a body camera assists an injured man who was beaten up as multiple fights continue to break out

A man crouching for cover (C) gets hit with a bike lock as protesters use anything they have for makeshift weapons in the brawl

'A large number of fights have occurred and numerous fireworks have been thrown in the crowds,' Berkeley police said in a news release. 'There have also been numerous reports of pepper spray being used in the crowd.'

The police department later said that the protesters were expanding the area of their demonstrations.

Dozens of people have been pictured bloodied or otherwise injured as fights continue to break out in the California city.

Both groups threw rocks and sticks at each other, and even used a large trash bin as a battering ram, according to the LA Times. A bank even boarded up its ATMs before the rally as a precaution.

Berkeley Police Department spokesperson Officer Byron White told Buzzfeed News: 'The City of Berkeley police department is a small to medium-size department. Our police department total is 176. I can tell you most of that 176 is here today.'

He also said city officials did not receive protest permit requests from either group, but found out about them through social media and distributed flyers.

A Trump supporter runs at counter-protesters while pepper spray flies at him from an unknown source

A Trump protester holds a sign that compares the president to a Nazi as the fights break out around him in Berkeley

A pro-Donald Trump supporter is taken into custody by police during the competing demonstrations as dozens are arrested for displays of violence

A man pulls a knife in the crowd of protesters as things escalate between pro and anti-Donald Trump protesters in Berkeley

A bloodied Trump supporter yells as multiple fights break out between Trump supporters and anti-Trump protesters in Berkeley

Hundreds of people with opposing opinions on President Donald Trump threw stones, lit fires, tossed explosives and tear gas and attacked each other with makeshift weapons as police stood by

A man with spiked rings clenches his fists as he enters an area where hundreds of protesters on each side of the political spectrum fight one another

Berkeley Police tweeted a picture some of the weapons that they have confiscated throughout the day as violence plagues the California city

A woman is pepper-sprayed in the face as Tax Marchers fight with pro-Trump protesters at the 'Patriots Day' rally for free speech on Saturday

White also explained that because there was no official communication between the city and protesters, officers had to estimate how many demonstrators would show up.

He said: 'The amount of people at the park for the demonstration was in the hundreds.

'It's a challenge for us to keep that amount of demonstrators inside that area with the amount of people we had. It would require another level of force for us to do that.'

However, he explained that he does not think they underestimated the protests, saying: 'Every time we have a demonstration in the city of Berkeley, we learn a little bit from it'.

During the protests Berkeley police posted to Twitter a picture of some of the makeshift weapons they had already confiscated, including metal pipes and baseball bats.

Another aerial view shows what is occurring in Berkeley as pro- and anti-Trump demonstrators clash

An injured man lies on the pavement as another injured man (R), bloodied from a brawl, walks away from the madness

Demonstrators left the park eventually and walked along the streets of Berkeley when the fights started to break out

A man is hit over the head with a Trump flag as fights break out between two opposing political protest groups and police stand by

Canadian alt-right blogger Lauren Southern spoke at the event and criticized societal change and Kim Kardashian, the Los Angeles Times reported.

Demonstrators later left the park and proceeded to walk along Berkeley streets while police followed closely.

A weekly farmer's market held in the park was cancelled due to the planned demonstration.

But one vendor came to sell her wares anyway and told the LA Times: 'Rain or shine or fascism we will be here.'

The rally follows a March 4 confrontation planned by several of the same groups that left several people injured and led to arrests.

In February, protesters threw rocks, broke windows and set fires outside the UC Berkeley's student union building, where then-Breitbart News editor and provocateur Milo Yiannopoulos was set to speak.

His presentation was cancelled.

A man was left bloodied after beaing hit over the head by a Trump flag in one of many fights that broke out between Trump supporters and anti-Trump protesters in Berkeley

Anti and pro-Donald Trump protesters clash during the Patriots Day Free Speech Rally and look ready to punch each other. Many of the pro-Trump protesters showed up wearing helmets

Members of the California III Percent provide security at the Patriots day 'free speech' rally which turned violent early on Saturday

Members of an alt-Right group called the 'Oath Keepers' also provided security during the rally



