(CNN) -- North Korea turned up the temperature yet another degree on its neighbors Monday, warning that it would not give any advance notice before attacking South Korea. "Our retaliatory action will start without any notice from now," the North said in a statement carried by its official news agency, KCNA. North Korea said it was responding to insults from the"puppet authorities" in the South, claiming that there had been a rally against North Korea in Seoul, the South Korean capital. It called the rally a "monstrous criminal act." North Korea said last month it was withdrawing from the armistice that put the Korean War on hold in 1953. 5 things we still don't know about North Korea's nukes . Timeline: War of words escalates . CNN's Esprit Smith contributed to this report.
NEW: North Korea says it will strike "without any notice" Tensions have been increasing steadily on the divided peninsula .