Xu Ye’an, the 58-year-old deputy chief of China’s Bureau for Letter and Calls, killed himself under mysterious circumstances in his office this week, the latest in a series of high-ranking officials to commit suicide recently.

Simon Denyer of the Washington Post reports that the deaths have led to speculation over whether President Xi Jinping’s high-profile and wide-ranging anti-corruption campaign is “putting so much pressure on his ruling Communist Party that some members were being driven to take their own lives.”

The circumstances leading up to the deaths lend some credence to this idea. Xu was not known to be under investigation, but one of his senior colleagues was recently fired for violating party rules, and his office—responsible for handling citizen complaints—has been the target of corruption allegations in the past.

Xu’s suicide follows that of Li Wufeng, the senior information office official referred to as China’s “top Internet cop,” who jumped to his death from his sixth-floor office in March. The South China Morning Post reports that Li had been “questioned several times by Communist Party discipline officers over the past few months, but the nature of it was unclear.”

Zhou Yu, a senior Chongqing police official who hanged himself in a hotel room last week, had been instrumental in now-disgraced Mayor Bo Xilai’s crackdown on organized crime. Bo, who had been a rising power in the Communist Party, was sentenced to life in prison last year on corruption charges.

Other recent suicides include a building safety official in the city of Fenghua, where an aging apartment building had recently collapsed, and a senior official at a state-owned power company.

The timing of this could all be just a coincidence. China does have a fairly high suicide rate by international standards. But given the scale of Xi’s crackdown—182,000 officials were punished last year, according to official numbers—and the kind of sentences that these officials can face in the worst cases, it wouldn’t be surprising if some officeholders were under more stress than normal.