Kenya's two main presidential candidates have been holding separate public rallies at different locations in the capital, Nairobi, after filing their nomination papers.

President Daniel arap Moi - who is barred by the current constitution from running again - accompanied the ruling party candidate, Uhuru Kenyatta, to the election commission's office, before heading to central Uhuru Park for a rally.

The main opposition candidate Mwai Kibaki presented his papers before going to a public rally at Nyayo Stadium to launch his campaign.

Kenyans go to the polls on 27 December to elect a new president, members of parliament and civic authorities.

Shut-down

Fearing that two rallies could turn violent, many businesses closed in central Nairobi.

From dawn, the city was awash with supporters of the two main candidates cruising the streets of Nairobi.

Veteran Mwai Kibaki leads the main opposition alliance

They are wearing party T-shirts and hats and have been chanting slogans and waving flags.

Addressing a crowd estimated at 35,000, 42-year old Uhuru Kenyatta hailed the new generation in Kenya, distancing himself from President Moi and his 71-year old opponent, Mr Kibaki, who is himself a former vice president.

"This is an opportunity that has been given to a new generation to bring fundamental changes in this country... bring new ideas in the leadership of this country," he said.

The ruling party Kanu faces its stiffest challenge from a united opposition after a 40-year grip on power since independence in 1963.

A coalition of 13 opposition parties has rallied behind Mr Kibaki, who is campaigning for change.

Mr Kibaki promised free and compulsory primary education for all saying Kenya and Somalia were the only countries in Africa where fees had to be paid. Kanu has suffered a string of defections by its senior leaders following Mr Moi's choice of Uhuru Kenyatta as his successor.

Kenyan television stations have been covering the delivery of the nomination papers and the rallies live.

Six other presidential candidates - belonging to smaller opposition parties - are expected to file their nomination papers on Tuesday.