Beneath the battlefields of Kursk, a silent invasion was underway. Russian special forces spent four days in darkness, crawling through a claustrophobic pipe barely wider than a person's shoulders to emerge behind enemy lines. This is modern warfare at its most primitive and terrifying. Images showed how Russian troops carried out an extraordinary mission in the Kursk region, during which they penetrated deep into Ukrainian-held territory via a gas pipeline..Watch in for more details!