SEOUL South Korea 's disgraced ex-president Yoon Suk Yeol was detained for a second time Thursday over his declaration of martial law and held in a solitary cell pending investigations into accusations of insurrection. Yoon had plunged South Korea into a political crisis when he sought to subvert civilian rule on December 3, sending armed soldiers to parliament in a bid to prevent lawmakers voting down his declaration of martial law. He became South Korea's first sitting president to be taken