Some were impaled to the ground with bayonets. Others were shot in the back while trying to escape.
Human rights groups and residents say up to 3,000 people died in a government-sanctioned operation in February 1984 meant to crack down on ethnic Somalis who were holding illegal weapons.
This week, a Kenyan government truth commission has for the first time started holding public hearings to investigate alleged human rights violations by government forces against residents in Kenya's northeast.
The killings occurred at Wagalla airstrip, a town some 310 miles (500 kilometers) northeast of the capital, Nairobi. One witness said survivors were forced to load the dead into trucks and the bodies were dumped in the hinterlands, said one witness.
"Some people were not dead, only unconscious, but they were put in those trucks and died after being dumped," said Roble Mohammed, 60.
Mohammed said he slipped quietly out of a police truck that was being used to ferry men to the airstrip. There they were forced to strip naked and lie on the tarmac. Mohammed 's cousin, 20-year-old Hared Ali, died on the tarmac.
Prime Minister Odinga earlier this year said that the commission will give an account of what really happened in Wagalla _ "why and on whose order."
Neither police spokesman Eric Kiraithe nor military spokesman Bogita Ongeri could be reached Tuesday for comment about the allegations.
The commission's investigation is part of a wider effort to establish the truth behind historical violations that are partly blamed for Kenya's 2007-08 postelection violence that killed more than 1,000 people.
State sponsored killings, human rights abuses, economic crimes and political assassinations dot Kenya's postcolonial history. The violations have created animosity between communities and helped fuel the postelection tribal violence, according to a 2008 government report into the post-vote chaos.
Historical injustices have "created an underlying climate of tension and hate, and the potential for violence, waiting to be ignited and to explode," the report said.
As part of the deal that ended the election violence, Kenya's coalition government formed a Truth, Justice and Reconciliation Commission to restore relations between communities and avoid violence in the 2012 vote.
The commission will hold public hearings throughout the country to attempt to establish the truth about large-scale violations like the 1984 killings. Unlike most other countries' truth commissions, Kenya's can recommend prosecution and the compensation of victims.
Former South African President Nelson Mandela formed a truth commission in South Africa to investigate human rights violations during apartheid and reconcile victims with the aggressors.
Some 3,000 people attended Monday's hearing, which focused on alleged violations by government security forces in the 1980s. The meeting, held in Garissa, the regional headquarters of Kenya's North Eastern province, was described as highly emotional.
"You really can't move forward until you have dealt with what is behind you," said Ronald Slye, one of three international commissioners working for the Kenyan commission.
Slye, a law professor at the University of Seattle, said the Kenyan commission is unique because it will also look into economic crimes, including the explosive issue of illegal land allocations.
The commission, however, is facing credibility concerns. Former chairman Bethuel Kiplagat is accused of human rights violations, including involvement in the killings in Wagalla, while he was working for the government. He first refused to leave office but resigned in November.
Harun Ndubi, a human rights lawyer, said he thinks the commission will fail because it has employed some of the victims of injustices.
The government also delayed in releasing funds for a year, Ndubi said, which has left the commission with little time before its mandate expires in November. Slye said the government could extend the commission's term to compensate for the time lost, he said.
Ozonnia Ojiello, an expert on peace building and conflict prevention at the U.N.'s office in Kenya, said questions of credibility have arisen in nearly all truth commissions in Africa but they have succeeded in doing their work.
Slye said the biggest challenge for the commission now is to get perpetrators of the crimes to make disclosures. For the victims, Slye said, there may never be closure.
"I am not sure one ever closes this thing," he said. "Victims I have spoken to in other countries says it is never over. What you learn to do is to live with it."