Updated

Thousands of protesters formed a human chain in Dresden on Saturday, determined to stop neo-Nazis from exploiting the German city's painful history on the 65th anniversary of its deadly Allied bombing in World War II.

Heavy security including riot police was in place to prevent clashes between the two groups, and five police helicopters flew overhead to monitor the crowds.

Neo-Nazis have caused outrage in the past by comparing the 1945 bombing of Dresden to the Holocaust and far-right organizers of Saturday's protest characterized it as a "mourning march."

Some 5,000 far-right supporters poured into the city, according to police, who limited them to a rally rather than a march for security reasons.

Across the Elbe River, some 10,000 people joined hands to create a human chain symbolically protecting the restored city center from neo-Nazis, after the city mounted an unsuccessful legal challenge to block the far-right march.

"Dresden doesn't want them and this gang doesn't belong here," Mayor Helma Orosz said.

The human chain helps to "make Dresden a fortress against intolerance and stupidity," and the anniversary provided a reminder of who started the war, she added.

There were some minor skirmishes, with some barricades set ablaze but quickly extinguished, and a car flipped over. A busload of far-right supporters was turned back after its headlights and windows were smashed.

Police reported some minor injuries, including people hit by rocks, but said the opposing sides were largely kept separated.

Three successive waves of British and U.S. bombers on Feb. 13-14, 1945, set off firestorms and destroyed Dresden's centuries-old baroque city center.

The total number of people killed in the Dresden bombing has long been uncertain. In 2008, a panel commissioned by state officials found that the firebombing killed no more than 25,000 people — far fewer than scholars' previous estimates that ran as high as 135,000.

Dresden has been rebuilt painstakingly over the years. Its landmark domed Frauenkirche, or Church of Our Lady — for decades no more than a mound of rubble — reopened in 2005.

Karolin Hanebuth, 20, came from Hannover in western Germany to counter the far-right protest.

"Fascism is not an opinion, it is a crime," she said.

The far right is marginal in Germany and has no seats in the national parliament. However, Saxony, where Dresden is located, is one of two eastern German states where the far-right National Democratic Party has seats in the regional legislature.