An outbreak of malaria has killed over 4,000 people in Burundi so far this year, the United Nations said Wednesday, a dramatic rise over the 700 victims the government announced just two weeks ago.

There have been over 9 million cases of malaria in the East African nation since January 2016, according to the report by the U.N. humanitarian office. Burundi, one of the world's , has a population of about 11 million.

The malaria cases are "well beyond the epidemic threshold," the report said, citing World Health Organization investigators.

The outbreak is the latest crisis for Burundi, which has been wracked by deadly political violence since 2015 and faces that the U.N. says have left nearly one in 10 people severely food insecure.

The political crisis began with President Pierre Nkurunziza's ultimately successful decision in April 2015 to seek a third term, which critics called unconstitutional. Hundreds have been killed, and more than 380,000 Burundians have fled into neighboring countries.

The U.N. estimates that the number of people affected by increased from 2.1 million to 3 million between October and January, the report said.