"Muslims are welcome here", was among the popular chants from the counter-protesters, who appeared to outnumber those gathered for the March Against Sharia event, which was one of almost two dozen planned across the country.
But Liyakat Takim, a professor of Islamic studies at McMaster University in the Canadian city of Hamilton, Ontario, says most Muslims don't want to replace USA law with Islamic law, known as Shariah.
The protest in Seattle was among dozens of demonstrations that took place across the country on Saturday.
Demonstrators on Saturday rallied to protest Islamic law, saying it is incompatible with Western democracy.
The rally began around 10 am and saw heated moments between Anti-Sharia law proponents and Anti-Trump counter protesters.
The Minnesota State Patrol says seven arrests were made during a "March Against Sharia" protest and counter-protest at the Capitol Saturday.
A similar scene played out in a park near a NY courthouse, where counter-protesters sounded air-horns and banged pots and pans in an effort to silence an anti-Sharia rally.
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In fact, USA think tank, Centre for Security Policy published this study showing a large fraction of United States based Muslims do indeed want sharia to replace U.S. constitutional law.
The Southern Poverty Law Center classifies several of the organizations involved in the March Against Sharia as hate groups with radical anti-government views and anti-Muslim associations.
Omsaf said people at the March Against Sharia don't understand enough about Islam, and makes him think he needs to do more to share the truth about his faith. "They want to totally dominate women", said one protester. "That doesn't mean we allow it today, too", he said. Lahring, a grandmother of 10, said she was there not to protest immigrants or Muslims, but to voice a concern that the country's laws and Constitution need to be protected. Gabriel has said that a "practicing Muslim, who believes in the teachings of the Quran, can not be a loyal citizen to the #United States of America". "Laws are amenable to change". "We often have a large group of people who pay the price for the actions of a few, and recently we've seen actions perpetrated by people who claim to be inspired by Islam", said Korn.
Molly Freiburg, 33, of Philadelphia, was one of the counter-protesters but not part of the larger group clad in black.
The anti-Shariah demonstrators yelled "commie scum!" and counter-protesters shouted "Nazis!" as the two sides squared off, after some of the counter-protesters crossed the street and approached the rally. The high figure for the counter-rally was roughly 70 people. The rallies occurred near a building developed by President Donald Trump.
In a 2007 interview, she infamously said "every practicing Muslim is a radical Muslim". The gathering was conversation based; a lot of people were there chatting with each other and holding sings that said have a 'Blessed Ramadan, ' 'Peace Be Upon You, ' and a sign in Arabic that says: 'All are welcome here'.
Refuse Fascism, a coalition of activists advocating confrontational tactics to oppose what it calls the Trump "regime", said it would show up at the rallies "to counter the xenophobic hatred and lies, defy intimidation and drown it out".