Kenya's defense chief and nine other senior military officers died in a helicopter crash in a remote area of the country on Thursday, President William Ruto announced.

"Today at 2:20 pm, our nation suffered a tragic air accident... I am deeply saddened to announce the passing on of General Francis Omondi Ogolla," Ruto told reporters, adding that nine other officers were also killed while two survived.

He said the Kenya Air Force has dispatched an air investigation team to establish the cause of the crash, which took place in Elgeyo Marakwet county, about 400 kilometers (250 miles) northwest of the capital Nairobi.

"A distinguished four-star general has fallen in the course of duty and in the service of the country," Ruto said, announcing three days of mourning from Friday.