"Most of them were hacked to death when arsonists stormed villages and set houses ablaze," he said.
The death toll from a month's violence now stands at nearly 800, while at least 260,000 have been displaced since December 27.
In normally peaceful Nakuru, another town in the Rift Valley province, a mortuary worker said on Monday that 64 corpses were lying in the morgue, all victims of the past four days of ethnic fighting.
The police also clashed with rioters in the western city of Kisumu.
A stronghold of Raila Odinga, leader of the opposition Orange Democratic Movement (ODM), demonstrators set several shops on fire, barricaded roads and lit bonfires across the city, witnesses said.
Police responded by firing in the air. Hundreds of people, meanwhile, fled to the city's central police station to escape the riots.
"We are trying to restore law and order in the towns," a police commander told AFP news agency. "The situation is tense at the moment."
While ethnic clashes have accompanied past Kenyan elections, the scale of the violence this year has been far worse.
It has mainly pitted ethnic groups which support the opposition because they feel marginalised, against the Kikuyu tribe of Mwai Kibaki, Kenya's president.
But the violence has taken a new twist in recent days.
Mohammed Adow, Al Jazeera's correspondent in Kenya, said: "In the first place it was opposition supporters attacking those perceived as government supporters based on their ethnic identity [but] we are now seeing revenge attacks.
"People who were earlier on the receiving end, are now the aggressors, as witnessed in both in Naivasha and Nakuru."
Human-rights groups say that the latest fighting is premeditated, with those involved being trained and paid.
Muthoni Wanyeki, the executive director of the independent Kenya Human Rights Commission, told Al Jazeera: "What happened in the Rift really was organised militia activity.
"We have some of the names of training camps, we have some of the names of pay masters [but] we are still trying to trace the line of command."
Wanyeki said several organisations had warned of an expected spike in violence, after militias began reorganising.
She also called on the government to bring security to temporary camps set up for the thousands of people who fled their homes to escape the violence.
Wanyeki said: "They are still not secure.
"The state seems to have surplus of forces to stop people from holding rallies in Nairobi, but not have enough forces to protect the remaining camps in the Rift Valley, which is ridiculous."
Odinga, who ran against Kibaki in the election, alleges that vote rigging robbed him of the presidency.
Kibaki has said he is open to direct talks with Odinga, but that his position as president is not negotiable.