The Burundian government is banning three U.N. human rights investigators from entering the country following the release of a report that cited serious rights violations in the East African country.

A letter on Monday signed by Foreign Affairs Minister Alain Aime Nyamitwe said U.N. investigators Pablo de Greiff of Colombia, Christof Heyns of South Africa, and Maya Sahli-Fadel of Algeria are no longer welcome in Burundi.

The three investigators from the U.N. High Commissioner for Human Rights are connected to a report released last month that implicated Burundian government officials in serious rights violations targeting the government's opponents.

Hundreds of people have died since President Pierre Nkurunziza pursued and won a third term that his opponents said was unconstitutional.

Last week Burundi threatened to withdraw from the International Criminal Court after the Hague-based court said it will investigate ongoing violence in Burundi.