Ling Jihua, the one-time top aide of former president Hu Jintao, is likely to face the same fate as disgraced Chongqing party chief Bo Xilai, mainland analysts say. Ling, 58, is the latest "big tiger" to be targeted by President Xi Jinping's anti-corruption campaign, though it is unclear if more senior figures are to be pursued. Following the downfall of Bo, investigations were launched into the former security tsar Zhou Yongkang , and the former vice-chairman of the Central Military Commission, Xu Caihou. In a brief statement on Monday, the party's anti-graft agency said only that Ling was being investigated for "suspected serious disciplinary violations". Zhang Ming, a political scientist at Renmin University, said it was unlikely that Ling would face only a party disciplinary hearing. Rather, he could expect a trial similar to Bo, who was expelled from the party in 2012 and sentenced to life in prison last year for bribery, corruption and abuse of power. "Judging from previous examples such as Bo, it's highly unlikely that Ling, Xu and Zhou will receive only punishment within the party. Otherwise all the fanfare would have been unnecessary," he said. Other analysts said the downfall of the four was the result of not only the anti-graft drive, but a political struggle within the party. Beijing-based political commentator Zhang Lifan said it was a tradition for the party to remove political foes by charging them with economic crimes. "Now that corruption is rampant within the party, using the name of anti-corruption is better than using purely political measures to defeat an enemy." There is mounting speculation that the four "tigers" were closely linked. An article published on the WeChat account of People's Daily quoted statements by Xi saying that "forming factions" within the party should not be allowed. Zhang, though, said more turbulence was likely as political factions were a way of life. In a surprising move last week, Ling wrote an article for the party magazine Qiushi, in which he quoted Xi at least 16 times. This was seen both as a gesture of loyalty and a show that he still had supporters. "It's a signal that the political struggle is not over yet," said professor Peng Peng, from the Guangzhou Academy of Social Sciences. "It's hard to say who's next, but it's quite unlikely to be someone with a state-level position. There should be a bottom line, otherwise there will be too much negative influence." Any careless move could "spit out sparks, and the leadership should be aware of this", he said.