Police said one person was shot at a Milwaukee protest on Sunday and officers used an armored vehicle to retrieve the injured victim and take the person to a hospital, as tense skirmishes erupted for a second night following the police shooting of a black man.

Some two dozen officers in riot gear confronted about 150 people who blocked an intersection near the fatal shooting Saturday afternoon, and more arrived. Police moved in to try to disperse the crowd and warned of arrests after protesters threw bottles and rocks at police and shots were fired.

Earlier Sunday, police Chief Edward Flynn said the man whose death touched off Saturday night’s rioting was shot after he turned toward an officer with a gun in his hand.

Wisconsin Gov. Scott Walker put the National Guard on standby for any repeat of violence. Protests were peaceful most of Sunday evening before the confrontation after 11 p.m.