One of the top PLA officers leading the Chengdu military area command has been detained amid graft allegations, several sources said, making him the latest high-ranking officer to fall in a sweeping effort to clean up the image of the world's largest fighting force. Investigators took Yang Jinshan , a lieutenant general, to Beijing last week as part of a corruption investigation, four sources said. His family members and secretary were also detained. The sources, including people with connections to the military, said the investigation into Yang, 59, and other senior military officials was part of the wider inquiry into Xu Caihou, a former vice-chairman of the powerful Central Military Commission. Xu, who was the military's second-highest career serviceman until he retired last year, has been accused of accepting bribes. He was expelled from the Communist Party last month. Xinhua has reported that President Xi Jinping approved the expulsion and the decision to hand Xu to military prosecutors at a Politburo meeting on military discipline. Yang established himself in the 14th Army Corp, based in Yunnan province and under the jurisdiction of the Chengdu military area command. One of the founders of the corp was Bo Yibo , father of the disgraced Bo Xilai . Bo Xilai visited Yunnan not long after his right-hand man Wang Lijun sought refuge in the US consulate in Chengdu in February 2012. Since that visit, some of the senior officers of the corps have been replaced, prompting speculation about whether the reshuffle was linked to Bo. Yang is the deputy commander of the Chengdu military area command, one of seven across the nation. He is also a member of the party's Central Committee and served as commander of Tibet's provincial military area. Two PLA major generals with backgrounds that overlap Yang's were detained previously: Ye Wanyong , the retired commissar of the Sichuan provincial military area, and Wei Jin , a deputy commissar of the Tibet military area. Ye, who is in his 60s, is said to have given a large amount of gold to Xu, a source said. Authorities have also searched his home. The scrutiny of the PLA comes as Xi, who chairs the Central Military Commission, moves ahead with an overhaul of the army's leadership in an attempt to root out corruption. In the latest round of promotions this month, Xi elevated about two dozen younger officers to the rank of lieutenant general and four more to general. The four have backgrounds in the Nanjing military area command, which covers Fujian , Zhejiang and Shanghai, where Xi spent more than two decades of his career. Analysts have said Xi is trying to put in place top officers who are loyal to him.