AlQa'dah 6, 1436, Aug 21, 2015, SPA -- North Korean leader Kim Jong Un ordered his troops onto a war footing from 5 p.m on Friday after his government issued an ultimatum to Seoul to halt anti-Pyongyang propaganda broadcasts by Saturday afternoon or face military action, Reuters reported. South Korean Vice Defence Minister Baek Seung-joo said it was likely the North would fire at some of the 11 sites where the loudspeakers are set up on the South's side of the Demilitarised Zone (DMZ) separating the countries. Tension escalated on Thursday when North Korea fired four shells into South Korea, according to Seoul, in apparent protest against the broadcasts. The South fired back 29 artillery shells. Pyongyang accused the South of inventing a pretext to fire into the North. Both sides said there were no casualties or damage in their territory, an indication that the rounds were just warning shots.