With a group of white supremacists yet to show up for a planned rally on the lawn of City Hall, at least two people have been injured in a steadily growing crowd of counter-protesters -- developments that prompted the Los Angeles Police Department to enter tactical alert.Some 150 white supremacists are scheduled to rally at the City Hall's north lawn at 1:30 p.m. More than 300 counter-protesters began to assemble there several hours earlier.Just before noon, a bare-chested, middle-aged man with Nazi insignias tattooed to his chest and back entered a crowd of counter-demonstrators near the corner of First and Spring streets.Counter-demonstrators surrounded him, chanting, "Nazi scum." One pushed a sign in his face and another jostled him. He was bobbing his head mockingly as the crowd chanted, when pushing suddenly broke out and about a dozen protesters began showering him with punches and kicks as he fell. The wood handle of one sign was smashed so hard into his back it snapped.Other protesters tried to protect the man. "You can't fight hate with hate," shouted one.After about a 15-second beating, an undercover police officer began shouting and flashed his badge. He pulled the man, bleeding from a gaping wound in the back of his neck, from the mob and past the yellow tape blocking the protesters.

In another area, a woman collapsed and was taken away by paramedics. It was not clear why she had collapsed.

-- Robert Faturechi and Richard Winton

[For the record: Photos previously included in this post showed an incident separate from the one described above.]