Simmering tensions between federal agencies and private charities about the resettlement of Cuban refugees burst into the open yesterday as the U.S. Catholic Conference called a news conference here to blast the Carter administration's handling of the crisis.

"You can't send a person out into the community with two bars of soap, a pair of shoes and a razor blade and nothing else -- unless you want them to slit their throat," said McCarthy, director of the U.S. Catholic Conference's Migration and Refugee Services Program.

Unlike Southeast Asians, Ethiopians and Eastern Europeans, Cubans have not been granted refugee status and therefore are not eligible for medical benefits, for food stamps in some states or for supplementary income payments, McCarthy said.

And, since the Cubans are not officially called refugees, agencies such as the U.S. Catholic Conference -- which is resettling more than half of them -- are not eligible for the $500 per refugee they normally would receive to cover the costs of finding sponsors, renting apartments, looking for jobs and other services.

"The resettlement is supposed to be a partnership between the churches and synagogues and the federal government," McCarthy said. "In this particular case, the federal government is not carrying their share. We will not be a party to dumping these people on the communities."

The administration so far has chosen to categorize the Cubans as "applicants for asylum" rather than refugees, mainly because of the cost, which it estimates could run as high as $300 million.

The State Department fears that granting refugee status to the Cubans would also encourage Castro to keep sending more people.

But pressure is mounting from refugee assistance groups and state officials, who say that the financial burden will fall upon them.

Pennsylvania Gov. Dick Thornburgh yesterday wrote to 25 congressmen and two U.S. Senators from Pennsylvania asking that the Cubans be designated as refugees under the 1980 Refugee Act.

"Such a designation would allow states to receive full federal reimbursement for up to three years to support the refugees and provide appropriate social and medical services," he said. Up to 20,000 Cubans are expected at Fort Indiantown Gap, Pa. by the end of the week.

The Catholic Conference, which has spent $600,000 on resettling the latest wave of Cubans, is smarting under accusations that it is not moving fast enough. Disturbances at several camps this week as Cubans sought to escape overcrowded conditions and join their families increased the pressure.

McCarthy said yesterday: "If we had the definition of refugees, we could clean those camps out.It costs $1,000 to resettle one refugee. We could be faster, but we need a little oil for the wheels."

McCarthy complained that although private agencies have resettled two million refugees here since World War II," there is today a total lack of understanding of the role of these agencies on the part of the government coordinating bodies. I try to get FEMA on the phone and I get no results."

FEMA, the Federal Emergency Management Agency that normally copes with hurricanes and other natural diasters, has taken charge of the refugee camps.

"I think we're doing a fantastic job of resettling," said FEMA spokeswoman Loretta Bacon. "So far, we've resettled 38,929 out of 85,090. We're resettling as fast as possible.

Most of the refugees have been placed with family members and friends.

Donald Hohl, another Conference official, complained that the Cuban program is under the "divided authority" of State Department refugee coordinator Victor Palmieri and White House adviser Jack Watson.

"It's not clear who's running the show, and that makes it very difficult to move the refugees out at the camp level," Hohl said.

A State Department spokesman said Watson has overall responsibility for coordinating policy, while Palmieri works with him.

Meanwhile, in Key West yesterday, about 200 angry boat-owners demonstrated outside the federal building to protest the government's seizure of more than 700 boats that had transported refugees from Cuba.

United Cubans, a group led by Miami Businessman Wilfredo Navarro, threatened massive demonstrations if the government denies their request to fetch more refugees. Only 100 or so boats are left at Mariel, in Cuba, and the U.S. Coast Guard is not permitting any more to leave Florida.