Police in Derry were working with community representatives tonight to stop stone throwing incidents in the city centre.
Officers were called to Fountain Street, Bishop Street, Society Street at around 7pm.
Police vehicles also were targeted as officers dealt with the situation.
Community leaders were urged to do all they could to ease tension.
By 11.30pm, the Police Service of Northern Ireland reported that the volume of attacks appeared to be decreasing.
Some stone throwing into Bishop Street was still taking place.