The two men who emerged from the white Datsun identified themselves as Kenyan police officers. They demanded that Erusani Kizza, a former Ugandan soldier who has lived in Kenya for several years as a refugee, get into their car. When he resisted, they struck him and shoved him inside, where a third man pointed a pistol at his head and forced him to lie face down on the floor.

Then, according to the account Kizza gave the Office of the U.N. High Commissioner for Refugees (UNHCR) here, he was driven for several hours while the men questioned him on the whereabouts of leading Ugandan refugees with whom Kizza had come in contact. Later he was forced into the trunk, where he said he saw a diplomatic license plate that had been removed from the bumper. He said he escaped an hour later by forcing open the trunk.

Kizza's abduction last month was the latest of nearly two dozen kidnap attempts against Ugandan refugees living in Kenya during the past two years, eight of them since January, according to press accounts, U.N. officials and refugees. Many of the attempts have failed, but in several instances, refugees either have disappeared or have resurfaced inside government prisons in Kampala, the Ugandan capital.

Refugees here are convinced the abductions are authorized by senior Ugandan officials and carried out by their agents, who appear to operate freely inside Kenya. They have also charged that members of Kenya's Criminal Investigation Division and its Special Branch police force have participated in the operations. Both Ugandan and Kenyan authorities have denied these allegations.

The kidnapings are an extension of the war for control of Uganda, where four guerrilla movements are challenging the government of President Milton Obote.

The largest, the National Resistance Movement of Uganda, is supported by many of the refugees and is reported to receive money and some arms and other supplies via Kenya.

U.S. diplomats have alleged in recent weeks that between 100,000 and 200,000 Ugandans have died since Obote returned to power in December 1980 and began a crackdown on armed dissidents. The government itself recently provided its own estimate that 15,000 had been killed either by dissidents or government troops.

The U.N. refugee agency estimated that about 215,000 people have fled to Sudan, Tanzania, Zaire and Kenya to escape the fighting.

Nearly 3,500 Ugandans have registered as refugees at the U.N. office here. Many are professionals who said they fled Uganda after threats against their lives and families. Among the 10 interviewed for this story were the former board chairman of a major government enterprise, a former opposition member of parliament and the former head of a department of the medical school at Makerere University in Kampala. Most were identified with the Ugandan Democratic Party, the major legal opposition political party in Uganda, although some served in the government or armed services during the rule of Ugandan dictator Idi Amin, who was overthrown in 1979.

With one exception, former member of parliament Abubakar Mayanja, all of the refugees asked that their names not be used.

"Our position here is extremely fragile," said one.

For years, the refugees felt secure in Kenya, whose government has been at odds with successive Ugandan governments ever since the collapse of the East African Community in 1977 amid bitter recriminations among its three partners -- Kenya, Tanzania and Uganda.

But the climate has changed markedly in the last year, following diplomatic overtures among the three states. While western diplomats have welcomed the regional thaw, it has meant new anxieties for the refugees.

Last fall, the governments of Kenya and Tanzania swapped political exiles, with Kenya returning three Tanzanians alleged to have plotted against Tanzanian President Julius Nyerere in exchange for two Kenyan airmen later sentenced to death for organizing the unsuccessful 1982 coup against President Daniel arap Moi.

At the same time, Kenyan Vice President Mwai Kibaki issued a public warning to refugees that "those who create mischief in one country and run into another country will have nowhere to go."

As a result, 10 to 20 of the most politically active Ugandans left Kenya, while those remaining have moved their activities further underground. They still distribute anti-Obote literature here and recently have produced and distributed a 90-minute video cassette that includes a graphic scene of tortured and mutilated corpses the guerrillas say they found on a farm 40 miles from Kampala. They allege that the farm was used as a dumping ground for bodies of victims murdered at the Makindye Army barracks outside Kampala.

The refugees contend that arms and funds for the guerrilla war come from inside Uganda, but one conceded otherwise.

"This is the gateway to Uganda," he said of Kenya. "All the sinews of war -- arms, ammunition, money and medical supplies -- pass through here."

An article earlier this year in Africa Now, a London-based monthly magazine, alleged that money and arms for the kidnapings of refugees are channeled through the Ugandan High Commission, or embassy, in Nairobi and that Kenyan policemen have been bribed to take part. It alleged that most of the kidnapings were authorized by Uganda's National Security Committee, chaired by Obote.

Despite official denials, some refugees also fear that the Kenyan government has been involved in some abductions. They cite the case of Balaki Kirya, head of the Uganda Freedom Movement, an anti-Obote organization, who was taken from his suburban Nairobi home in July 1982. One refugee has said he saw Kirya being escorted in handcuffs by police officers at the headquarters of Kenya's Special Branch here. A few days later, Kirya appeared in a Kampala courtroom to face treason charges. He is believed to have remained in prison ever since.

Officials at the Office of the U.N. High Commissioner for Refugees have recorded the accounts given by abduction victims and given publicity to some of their stories, but otherwise contend that they are able to provide little help.

"It's not our function to give physical protection to refugees," said UNHCR spokesman Hugh Hudson. "Something goes wrong, all we can do is try our best to assist them."

Hudson noted that the commission sent a high-level delegation here last fall to protest without apparent success the exchange of political exiles between Kenya and Tanzania. But he said it has not attempted to ascertain the numbers or fate of those who have been abducted back to Uganda, although the commission has helped relocate refugees who for reasons of personal safety have decided to leave Kenya.

"Unfortunately, it's not UNHCR's function to make inquiries about refugees who have been forcibly returned," he said. "It's a fait accompli and has to be recognized as such."