BOSTON - Thousands of people flooded the streets of Boston Saturday in protest at a planned gathering of white nationalists in the city, amid fears of clashes between the rival camps a week after a similar event turned violent in Virginia.

Around 4,000 anti-racism demonstrators were marching towards the historic Boston Common where a so-called “free speech” rally - expected to draw no more than a few hundred people - was scheduled to run from noon to 2 pm (1600 to 1800 GMT), according to an AFP photographer at the scene.

Authorities in the northeastern city, a Democratic bastion, ordered a strict ban on weapons in the area, and said the white nationalist rally would not be allowed to run overtime. “It’s time to do something,” said Katie Zipps, who travelled from Malden, north of Boston, for the counter-demonstration. “We are out here to add an extra body to add to the numbers of those who resist.”

While rally organizers vowed their demonstration would be peaceful, one scheduled speaker, Kyle Chapman, has claimed allegiance to a group called the “Fraternal Order of Alt-Knights,” described by the anti-hate organization Southern Poverty Law Center as a “new Alt-Right group of street fighters.”

Thousands of counter-protesters had convened in two groups before the main rally, chanting “No Nazis, no KKK, no fascists in the USA!” One man held a sign that read, “Stop pretending your racism is patriotism,” and a woman’s sign said, “Muslims welcome, racists out.”

There was a large police presence in the area, and heavy trucks and concrete barriers were used to block vehicle access.

“We will not tolerate violence or property violence of any kind,” Mayor Marty Walsh warned in a tweet. “I ask everyone to be peaceful today and respect our City. Love, no hate,” he added. “We stand together against intolerance.”

A young woman was killed last weekend when an avowed white supremacist rammed his car into a group of counter-protesters in Charlottesville, Virginia - and President Donald Trump’s muted response to the violence has plunged his embattled administration deeper into disarray.

In remarks throughout the week, state and local officials had emphasized that there was no place for hatred and violence in the historic Massachusetts city, but they also were preparing for any eventuality.

“I just think the rhetoric has really brought this to a different level and that’s what we’re worried about,” Boston Police Commissioner William Evans told reporters on Friday. “I’ve never seen so many people looking, almost looking for confrontation. You know, we gotta knock it down.”