Police say four people were shot and wounded when gunfire broke out at an anti-violence vigil in the U.S.

The Charlotte Observer reports that Mothers of Murdered Offspring sponsored the Thursday night vigil. They were calling attention to the death of a man who police say was fatally shot when he tried to rob a convenience store.

A police statement says officers were called by someone at the vigil who said a person pulled a gun and began firing.

Officers found no shooting victims at the scene but learned that each victim had called for help from a different location after the crowd scattered.

Police have made no arrests.