Pierre Nkurunziza, the president of Burundi, died of a heart attack on June 8, according to the government.

In a statement posted on Twitter on Tuesday, the government announced that the outgoing president, 55, died at Karusi hospital.

Nkurunziza, who has been in power since 2005, was to be replaced by Evariste Ndayishimiye in August.

Ndayishimiye was declared the winner of the May 20 presidential elections after garnering 68.7 percent of the votes.

Denise Bucumi Nkurunziza, President Nkurunziza's wife, was airlifted to Nairobi on May 28 for treatment after contracting COVID-19.

Bucumi was airlifted to the Aga Khan University Hospital following a government-to-government agreement using Amref's acquired portable isolation chamber, which is an innovative medical unit and transportation system designed for optimal safety during patient loading and transport, Nation Newspaper reported.