The trial of Bo Xilai may have divided the Chinese Communist Party and hogged the media spotlight, but, outside the courtroom, President Xi Jinping is continuing his steady efforts to consolidate control, clean up the party and sideline opponents, with a series of detentions and arrests in the past few days.

On Monday, a senior manager of China's giant oil company China National Petroleum Corp. was placed under formal investigation for "severe breaches" of Communist Party discipline, the government announced, the second executive from a major state-owned enterprise to face such a probe this month.

Xi has vowed to fight the vested interests that are thought to be blocking efforts to reform the country's economy, as well as eliminate both the "tigers" and the "flies" — the senior and junior officials — believed to be responsible for widespread corruption.