.Putin phones cross-border attack in Kursk region a 'provocation' The Washington PostRussia claims Ukrainian troops crossed into its region and also introduced 'substantial assault' CNNHow deep right into Russian region has Ukraine's shock August incursion arrived at? MeduzaUkraine Launches Rare Cross-Border Ground Assault Into Russia The New York City TimesRussia: State of urgent in Kursk surrounded by incursion DW (English).