NAIROBI, Dec 31: Kenya plunged further into chaos on Monday as fresh violence triggered by President Mwai Kibaki’s disputed re-election left more than 140 dead and Washington withdrew US endorsement of the result.

Defeated opposition candidate Raila Odinga rejected Kibaki’s victory and urged his supporters to turn out for his own alternative “inauguration” rally in Nairobi on Thursday as riots flared across the country with police opening fire on protesters and looters.

Kibaki, 76, was officially sworn in for a second term on Sunday despite widespread allegations of vote-rigging as he defied pre-election opinion polls to overtake 62-year-old Odinga’s early lead in the count.

Riots broke out almost immediately and police and mortuary officials said at least 75 people were killed in cities in western Kenya overnight and a further 48 in Nairobi’s massive slums.

Kenya’s ethnic rivalries, which traditionally flare up during election time, were fuelling the post-election violence, with six members of Kibaki’s Kikuyu tribe hacked to death Monday in Mombasa.

The Kikuyus, the country’s largest tribe, responded immediately, killing three Luo, the second largest grouping to which Odinga belongs. Another 10 people were killed in Mombasa in separate incidents, police said.

Foreign governments warned their nationals to avoid non-essential travel to Kenya, while tour operators called off local excursions for tourists already there.

The overnight fatalities mean that 162 people have now been killed since Thursday’s elections, which have severely undermined one of Africa’s more stable democracies.

The credibility of the result was questioned by Britain, the United States and the European Union’s team of election observers.

Washington had initially congratulated Kibaki on his re-election but the US State Department expressed on Monday “serious concerns” about the vote count and rowed back from its endorsement the day before.

“We do have serious concerns, as I know others do, about irregularities in the vote count, and we think it’s important that those concerns... be resolved through constitutional and legal means,” department spokesman Tom Casey said.

Around 53 people were killed in Kisumu, kenya’s third city and an Odinga stronghold.

Kisumu police chief Grace Kaindi declined to comment on the number of dead, but acknowledged that officers had opened fire on “looters” during the night.

Police clamped a day-time curfew on the city, with an order to shoot violators.—AFP