Kenya’s former president, Mwai Kibaki, is dead.

Kibaki died at the age of 90, President Uhuru Kenyatta has announced on Friday in an address on state television.

“It is a sad day for us as a country. We have lost a great leader,” Kenyatta said.

Kenyatta added that Kibaki had “led the charge to keep the ruling party accountable” and had “earned the abiding respect and affection” of this nation.

He also declared a mourning period until Kibaki’s burial, with the flying of flags at half-mast.

Kibaki was victorious in the 2002 and 2007 elections, both of which descended into violence.

His 2002 election ended 40 years of one-party rule since independence.

However, his 2007 re-election sparked months of nationwide violence and led to 1,200 deaths.

Kibaki is survived by four children.