NAIROBI, Kenya — One month after a scathing United Nations report that called for a criminal investigation likely to lead back to its leaders, Burundi has withdrawn from the International Criminal Court, becoming the first country in the world to do so.

A United Nations Commission of Inquiry on Burundi reported in September that it had found evidence of extrajudicial killings, disappearances, arbitrary arrests and detentions, torture and sexual violence in the two-and-a-half years since Burundi’s president, Pierre Nkurunziza, muscled his way to a third term in office.

Burundi announced its intention to withdraw last year, at a time when the court was deeply unpopular with African leaders. Gambia and South Africa were also threatening to pull out, and the continent’s top intelligence officials signed a statement accusing the court of being “hijacked by powerful western countries” and “acting as a proxy” for foreign-led government change. But Mr. Nkurunziza can no longer count on leading a wave of exits.

Gambia reversed course on its threat after Yahya Jammeh, its president for 22 years, departed following his electoral defeat by Adama Barrow. South Africa revoked its withdrawal in March, after its High Court ruled that Parliament would have to approve the measure.