(Adds Kibaki comment)

By Duncan Miriri

NAIROBI, March 3 (Reuters) - Kenya's political rivals vowed on Monday to hasten talks to resolve longstanding disputes over land and wealth behind a post-election crisis that ruined the country's image as one of Africa's most stable democracies.

But in a grim reminder of how much work remains, 12 people were killed and six seriously burned on Monday in the latest in a series of land clashes in the Mount Elgon region near the Uganda border.

"As a result, 12 people were killed ... Ten houses were burned to ashes and six people were seriously injured," police spokesman Eric Kiraithe said in a statement.

The victims -- five children, four women and three men -- were from three families and were either burned, shot or hacked to death after a rival subclan of the Kalenjin tribe accused them of giving information to their enemies, he said.

The attack appeared to be unrelated to the waves of violent ethnic conflict that broke out after President Mwai Kibaki's disputed re-election in a Dec. 27 vote. Mount Elgon for more than a year has suffered bloody property feuds.

Kenyans exhausted by more than a month of looting, rioting and ethnic killings have welcomed a power-sharing deal signed last week to end turmoil that has driven away tourists and dampened economic prospects.

Having brokered the deal, former U.N. boss and chief mediator Kofi Annan urged Kenyans to support the agreement and hold their leaders to the promises -- including land and electoral reforms -- made to them.

Annan, who handed over day-to-day mediation to Nigeria's ex-foreign minister Oluyemi Adeniji, had said long-term issues should be resolved within a year, but political negotiators were hopeful they could speed up their work.

'MAJOR ISSUES'

"We are all unanimous that we are going to wind up tomorrow," government negotiator Mutula Kilonzo told reporters after discussions chaired for the first time by Adeniji.

Opposition negotiator William Ruto said the "major issues are really out of the way".

"What is remaining at the moment ... how to get to a new constitution in two months and the issue of setting up a truth, justice and reconciliation commission," he said.

Parliament is due to meet on Thursday to pass a constitutional amendment to allow for a coalition government led by Kibaki. His opposition rival, Raila Odinga, will take a newly created post of prime minister.

Kibaki said the agreement was good for the country.

"We all need to come together as a united nation so that we can move forward as one," he said.

More than 1,000 people were killed and 300,000 left homeless in violence that erupted when Kibaki was sworn in as president. Odinga says he was robbed of victory.

The turmoil was expected to cost Kenya 260 billion shillings ($3.8 billion) in the first half of the year, according to a Feb. 28-dated report by the Kenya Association of Manufacturers.

It said 100 billion shillings were lost in January alone, compared to the government's estimate of 60 billion.

In a "message of hope" published in the Daily Nation newspaper on Monday, Annan saluted Kibaki and Odinga for agreeing to share power and "in that single act of statesmanship, saved your beautiful country, which was about to self-destruct".

Despite the relief felt by most Kenyans, many are sceptical that the two men -- who fell out when Kibaki reportedly reneged on a previous agreement to create a prime minister's job for Odinga -- can overcome differences to work together. (Additional reporting by Bryson Hull, and additional reporting and writing by Katie Nguyen; Editing by Richard Meares)

AlertNet news is provided by