Thousands of protesters converged in Berkeley, California, Sunday for a "Rally Against Hate" in response to a planned right-wing rally.
He said "the potential use of force became very problematic" because thousands of mostly peaceful left-wing protesters were already inside the park.
The event was one of several rallies that had been called for Sunday in Berkeley, a day after a controversial freedom rally planned by Gibson in San Francisco fizzled amid throngs of counterprotesters.
Most of the 13 people arrested were locals from the East Bay, while others hailed from Oregon, Nevada and San Diego County.
"We've had enough", she said.
Gibson then went behind a line of police wearing riot gear.
Israel to let MPs visit flashpoint Jerusalem holy site
The meeting Thursday afternoon is part of a visit to the region by the US diplomats. Mr Kushner described the US-Israel relationship as "stronger than ever".
As protesters chanted "No Trump, No KKK, No fascist United States of America", conservative rally organisers showed their support for President Donald Trump.
More than a dozen protesters were arrested Sunday during confrontations that broke out amid largely peaceful protests in Berkeley, California, authorities said.
More than 100 protesters dressed in black pushed past police barricades in a downtown city park and assaulted at least three people by punching and kicking them. Peaceful anti-Trump protesters expressed discontent with antifa; one woman told the LA Times that she anxious the march would be tied to violence, while another man said, "We need to get antifa out of here".
According to civil rights attorney and counter protester Anne Weills, campus police set up barricades to prevent cars from coming into the area, a reference made to the killing of Heather Heyer in Charlottesville, Virginia. It was expected to draw members of white supremacist and nationalist groups, but only a few far-right supporters have turned out. People at the park are also not allowed to cover their faces with scarves or bandanas. In a video he posted on Patriot Prayer's Facebook page, Gibson said he is a person of colour and so if he was in favour of white nationalism "I'd have to punch myself in the face".
Anti-rally protesters were chanting slogans like "No Trump".
The larger event was canceled on Friday, but city leaders say they don't trust the group, and fear an impromptu rally will appear in its place, or that unrest and violence may break out at the news conference at Alamo Park.
"The San Francisco Police Department has an enhanced presence at Alamo Square and in the surrounding neighborhoods", a police spokesperson told The Chronicle. If we don't stand against the attack on free speech in Berkeley, then it won't be long before it's in my neighborhood and I have to be anxious about my political beliefs.