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. The local Solinger Tageblatt newspaper said authorities had asked residents to leave the city centre. The festival was temporarily suspended and sirens…