Leftists battled Saturday with riot police escorting a march of far-right protesters in Dresden, Germany, dpa reported.
Much of the German city was destroyed, and thousands of Germans burned to death, by Allied firebomb raids late February 13 and early February 14, 1945. German neo-Nazis claim the Allies committed a war crime. Left-right clashes are common on the anniversary.
Eyewitnesses said several hundred leftists who objected to the far right holding a procession tried to attack neo-Nazi participants, hurling bottles at the police cordon and damaging parked cars.
Separately, thousands of pacifists took part in processions to both denounce the neo-Nazi threat and remember the city's dead.
Many mainstream Germans say that the huge loss of life must be remembered as a warning that war does not pay. The Dresden issue has been used by the right to entice Germans towards nationalism.
Organizers forecast the biggest rally against the right would be attended by some 15,000 people.
Historians say the massed air raid by the US and British air forces on Dresden led to 25,000 deaths, mainly civilians.
On Friday, the bell of the Frauenkirche, or Church of Our Lady, tolled in their memory. The church collapsed two days after the raids. US and British donors helped pay to rebuild the church in a gesture of reconciliation. It reopened in 2006.