Kenya's Chief of Defence Forces (CDF) Francis Ogolla is dead, President William Ruto has confirmed.

General Ogolla died on Thursday afternoon after a Kenya Defence Forces (KDF) helicopter crashed in Sindar, Elgeyo-Marakwet County, The East African reports.

"Today at 2.20 pm, our nation suffered a tragic air accident at Sindar area, Kaben location, Tot division, in Elgeyo Marakwet County. I am deeply saddened to announce the passing of General Francis Omondi Ogolla, the Chief of the Kenya Defence Forces," President Ruto said in a live address to the nation from State House, Nairobi on Thursday night.

The President said together with General Ogolla in the crash were 11 other military personnel, nine who also passed on while two survived.

The other officers who died in the crash are Brigadier Swale Saidi, Colonel Duncan Keittany, Lieutenant Colonel David Sawe, Major George Benson Magondu, Captain Sora Mohamed, Captain Hillary Litali, Senior Sergeant John Kinyua Mureithi, Sergeant Cliphonce Omondi, and Sergeant Rose Nyawira.

President Ruto also announced three days of national mourning, beginning Friday, April 19, in honour of General Ogolla and nine others who perished in the crash.

During this period flags will fly at half mast, the head of State said.

"This is a moment of great sadness for myself, as the Commander in Chief of the Kenya Defence Forces, the Kenya Defence Forces fraternity and the nation at large. Our motherland has lost one of her most valiant generals, gallant officers, service men and women," President Ruto said.

"The demise of General Ogolla is a painful loss to me, and certainly, the sorrow we all feel about his passing is shared by all the people of Kenya, and especially the KDF fraternity. A distinguished four-star general has fallen in the course of duty, and service to the country," the head of State added.

The President said a Kenya Air Force team had been dispatched to the site of the crash to investigate the crash.