Kararuza has previously worked as a deputy commander of an international peace force in the Central African Republic (CAR).
"He energetically fought against the coup plotters last year and exceptionally contributed in strengthening peace and security during and after elections," Nkurunziza said in a statement late on Monday.
"We humbly pray that with the help of God perpetrators of the shameful acts are arrested and quickly punished according to the law."
Tit-for-tat attacks between Nkurunziza`s security forces and his opponents have escalated since April 2015 when he announced a disputed bid for a third term as president and won re-election in July.
The U.N. says more than 400 people have been killed and over 250,000 have fled.
On Monday, the international war crimes court said it will investigate the rising violence in Burundi.
Nkurunziza`s opponents said his third term bid broke a peace agreement that ended a previous civil war while the government said a third term was legal, citing a constitutional court ruling.
The president won re-election in July.
Three armed groups, including one led by officers that attempted a coup in May 2015, have launched armed rebellions against Nkurunziza`s government.
More about:
-1780923278.jpg&h=190&w=280&zc=1&q=100)
