.Putin calls cross-border assault in Kursk area a 'justification' The Washington PostRussia states Ukrainian troops crossed into its region and also introduced 'substantial attack' CNNHow deep into Russian territory possesses Ukraine's surprise August incursion hit? MeduzaUkraine Launches Rare Cross-Border Ground Assault Into Russia The New York City TimesRussia: State of unexpected emergency in Kursk amidst attack DW (English).