ATLANTA, NOV. 27 -- A fifth day of stalemate in negotiations for release of 94 hostages held by Cuban inmates here led to growing frustration on the part of authorities and fueled concern about the course of the crisis.

Authorities also turned aside an offer by Miami's Cuba-born Mayor Xavier Suarez, who flew here today, to exchange himself for the hostages. "It doesn't fit with what we're trying to do," said FBI Special Agent Joe Hardy.

There had been some hope late Thursday that three prison guards would be released here after a face-to-face appeal by three prominent Cuban Americans from Miami, but a majority of the prisoners vetoed the plan.

Justice Department spokesman Thomas M. Stewart said authorities were "frustrated" by Thursday's stalled talks and as a result are taking a "firmer posture" in their dealings with the detainees.

A statement released by Stewart said the detainees "are not helping their position by being unable to deliver on proposals seriously discussed in the negotiations.

"By leading us to believe that they were prepared to resolve the situation, they have . . . raised the concerns and fears of the detainees' families as well as the families of the hostages," the statement said.

Stewart described continuing, intermittent negotiations with the inmates by telephone as "quiet" and "flat." Government negotiators, he said, "are waiting for new indications from the detainees."

Following the lead of other Cuban detainees in Oakdale, La., inmates here seized hostages Monday and Tuesday to protest a revived accord to deport 2,500 Cuban refugees, including the detainees, who arrived in the 1980 Mariel boatlifts. Attorney General Edwin Meese III promised a case-by-case review in hopes of ending the crisis.

Today, a Justice Department official said he is worried that the situation inside the prison might deteriorate rapidly if the detainees here are disappointed with the provisions of the prospective agreement in Oakdale.

"We could be here for 18 or 19 days," he said.

The official expressed further concern about how tense law-enforcement officers, who are being held at a state of readiness inside the prison grounds for a fifth day, might react, especially if inmates seek reprisals against hostage guards whom they perceive to have been abusive in the past.

But J. Michael Quinlan, director of the Bureau of Prisons, was more positive during a briefing for reporters in Washington. He said negotiations in Atlanta "continue to be productive." Although the situation is "not as close to resolution" as the one in Oakdale, Quinlan said, it is "much closer to resolution than it was yesterday."

Asked if a peaceful resolution at Oakdale would help end the Atlanta uprising, Quinlan told reporters, "They're not tied together, but it certainly is something we see as a very hopeful sign."

"The {inmate} leadership at Atlanta is still not quite at the level that it is at Oakdale, but they're very close to that level," Quinlan said.

This afternoon, men in windbreakers who appeared to be sharpshooters were visible for the first time atop a portion of the prison power plant that juts two stories higher than the prison walls.

It was shortly before noon on another gray, rainy day when Miami Mayor Suarez and a delegation that included five other Dade County elected officials who were born in Cuba arrived, seeking a meeting with the inmates.

Instead, they were greeted by government officials in a building on the prison grounds but outside the penitentiary proper.

There, an FBI agent adamantly opposed allowing Suarez or others in the delegation to meet with the protesting inmates. A Justice Department official also questioned the ability of the affluent, white Miami officials to relate usefully to the poor Cuban detainees, many of whom are black.

Quinlan said offers of help from Suarez and others were "very gracious." He said, however, that "at this point, we do not think we want to accept any of the offers of switching outside people for any of the Bureau of Prisons hostages."

Charles King, an Atlanta-based specialist in urban crisis management, lambasted Suarez's offer to take the hostages' place.

"The idea from the inmates' viewpoint is not to free the hostages," he said. "The point for them is what's going to happen to them."

The detainees' position, King said, is "ironic. America has mistreated these men for seven years, and they still say, 'We want to become American citizens.' " The government, King argued, could improve the negotiating atmosphere "with a lot of perks to secure their trust: to let them converse with their families, so they know the negotiators have a heart. Then the detainees could let the hostages talk with their families."

King noted that relatively few of the Cubans ordered deported had been imprisoned for violent crimes.

Quinlan told reporters, "I do not think the legal rights of the detainees have been violated or ignored."

The hostages' families remained gathered in army field tents on the prison grounds. Late Thursday, several tied yellow-ribbon bouquets to the outer fence of the prison grounds.

The Justice Department this afternoon issued a roster of the names of all Cuban detainees and U.S.-born inmates from the prison who have surrendered and been transferred to other federal facilities since the uprising began. The list, said to be mainly for the inmates' relatives, did not say where those men are.

Of the 1,148 inmates still inside the penitentiary here, all but 20 were born in Cuba. Staff writer Ruth Marcus in Washington contributed to this report.