Kenyan Vice President George Saitoti has declared his intention to stand for the ruling party's presidential nomination - challenging President Daniel arap Moi's own choice of a successor.

My service to this country has prepared me to handle the challenges of leadership.

George Saitoti

Mr Saitoti, who has been Kenya's vice president for 13 years, made the announcement on Tuesday on his arrival from an overseas trip.

His decision further highlights the tensions at the top of the ruling Kanu party, as other senior officials have declared their intentions to seek the party nomination in presidential elections due in December this year.

President Moi is required by the constitution to stand down at the end of his second five-year term and he wants Uhuru Kenyatta, son of Kenya's first President Jomo Kenyatta, to succeed him.

The BBC's Ishbel Matheson in Nairobi says Mr Saitoti's decision to run for the party's presidential nomination shows how deep the rift in Kanu is.

Defiant move

Mr Saitoti has, of late, been associated with a group seen as opposing Uhuru Kenyatta.

He was demoted from his powerful party post as vice chairman of the ruling party when Kanu and the opposition NDP merged in March.

"My service to this country has prepared me to handle the challenges of leadership," Mr Saitoti told reporters at Jomo Kenyatta International Airport.

Saitoti has been vice president for 13 years

"It is therefore just and appropriate that I respond affirmatively to the calls by the Kenyan people that I offer myself for the nomination."

Our correspondent says Mr Moi has been trying to head off an open revolt - now led by his own general secretary Raila Odinga who assumed the post after his NDP merged with Kanu.

Mr Odinga has declared he will contest the Kanu nomination and had earlier joined two other senior Kanu officials to form the "Kanu Rainbow Alliance" to push for a democratic vote to choose the party's next presidential candidate.

Two ministers have already been sacked for publicly criticising Mr Moi's choice of successor.