People were killed and injured in an attack at the 650th anniversary celebrations of the city of Solingen in western Germany, according to the police late on Friday evening. Police sources said a knife was likely involved. Armed officers are currently at the scene and have cordoned off large areas of the city and set up privacy screens. The incident took place in Fronhof, a marketplace in the city centre where a stage was set up for live music. Thousands of people were leaving the area, after the authorities called on residents to remain calm and go home, the local Solinger Tageblatt newspaper…