BEIJING (AP) — China's ruling Communist Party announced Tuesday it is launching an investigation into former domestic security chief Zhou Yongkang, who was once one of the country's most feared leaders. Bo Xilai ally 
 
 In a brief statement, state-run Xinhua news agency said the investigation would be conducted by the Communist Party's corruption watchdog, the Central Commission for Discipline Inspection.  BEIJING—China launched a formal investigation into one of the Communist Party's most senior figures, lifting a cloak of immunity that has shielded the country's highest ranks as President Xi Jinping made his boldest attempt yet to solidify power.
– Chinese President Xi Jinping has made it his mission to eliminate corruption within the ruling Communist Party, and his latest target is the highest-ranking thus far. Zhou Yongkang is the former head of national security and an ex-member of the Politburo Standing Committee, which heads the party; he was among "the country's most feared leaders" before he retired in 2012, the AP notes. But he hasn't appeared publicly in months, the BBC reports, and now, state media say he's facing an investigation over a possible "serious disciplinary violation." Though unspecific, that language tends to refer to corruption, the Wall Street Journal notes. Zhou, a onetime ally of disgraced politician Bo Xilai, is the highest-ranking official to face investigation since the 1980s, when Mao Zedong's wife was among those targeted in an investigation, the BBC reports. Until now, such inquiries had avoided Politburo members, the Journal notes. Xi could face anger within the party over the probe, the paper adds, but it also points to the solidifying of his power, the BBC notes.