ATLANTA, NOV. 29 (SUNDAY) -- Cuban inmates holding the federal penitentiary here for a sixth day released four of their 94 hostages early this morning, hours after setting billowing new fires in unoccupied prison buildings and issuing their first public demands.

At 12:30 a.m., an inmate spokesman announced that the hostages would be freed. Fifteen minutes later, two FBI agents escorted a camera crew to the prison's east entrance, where the four hostages emerged from a side door shortly before 1 a.m. and were escorted by authorities to a van that took them to a nearby building on the prison grounds.

Neither the inmates nor federal officials, who had cut off water to the prison as part of a tougher stance, explained the release.

Nearly 1,400 Cuban inmates overran the prison Monday, torching buildings and taking hostages, after news of a revived U.S.-Cuban agreement to deport about 2,500 of the 125,000 Cuban refugees who arrived in the 1980 Mariel boatlifts.

Attorney General Edwin Meese III offered a moratorium on such deportations and case-by-case review of the inmates' immigration status "in the expectation" that the uprisings here and at the federal detention center in Oakdale, La., would end.

Church and Justice Department sources said Auxiliary Bishop Agustin A. Roman of Miami flew Saturday morning to Oakdale, where inmates who have controlled the facility since Nov. 21 had asked him to witness an agreement for the release of the 26 remaining hostages there.

Justice Department spokesman Thomas M. Stewart said the release of the four hostages here came as a surprise, and there was "no quid pro quo" by the government. He said it seemed "a total goodwill gesture on their part. We view this as cause for cautious optimism."

The freed hostages were identified as Dr. Carl Gates, the chief prison psychologist; Dr. Walter Cassidy, the prison psychiatrist; Lawrence Greer and Manuel Echevarria.

Federal officials had been surprised earlier when an inmate spokesman, speaking alternately in Spanish and English over a two-way radio, demanded that the inmates be included under the 1966 Cuban Adjustment Act, which allows most Cuban refugees to become permanent residents after a year and to apply for U.S. citizenship.

Many of the Cuban inmates here lost their eligibility under the act when they were convicted of crimes before their immigration status was established. The broadcast was the first formal presentation of demands. Stewart said afterward that officials would respond within 24 hours, but perhaps only to ask questions about the demands.

"I think on the face of it those are extraordinary suggestions," he said.

The inmate spokesman, who delivered the same message over prison loudspeakers, said the hostages were safe and added, "To achieve our goal we are compelled to say that we will die before we say give up our hope for deserved freedom and liberty."

Later, the Cubans broadcast the voices of three hostages, all of whom said they were being well-treated and were sympathetic to the prisoners.

Saturday's first fire broke out about 7:30 p.m. in the solitary confinement building; a second fire broke out about an hour later in the education building. Both buildings were unoccupied and there was no word of any injuries as smoke and occasional flames licked above the prison's gray walls. Firefighters were unable to reach the blazes and let them burn themselves out.

The subsequent broadcast "to the people of the United States" on the prison's two-way radio caught prison officials off-guard. It began minutes after Stewart told reporters in a drizzling rain that there was no reason to believe that the fires were set as a negotiating tactic.

He said that although a telephone used for negotiating was temporarily out of order, the prisoners had radios and "if they want to send a message about the fires, they have the means to do it."

Asked moments later about the prisoners' demands, Stewart said, "There's no way of stopping them from communicating to the people of the United States. If they are serious about them {the demands} as negotiating positions, it can be discussed."

The radio message, broadcast repeatedly, said that the inmates have been "pushed beyond the human limits by the indefinite extension of our incarceration."

"That not only causes great personal suffering, but which has also included our dear family and relatives to suffer, and thus we are compelled to do what we have started here in Atlanta."

They listed these additional demands:That none of them be deported to Cuba.

That authorities release immediately all refugees who have completed their prison sentences for criminal convictions and are being held only for deportation.

That all refugees be protected by the U.S. Constitution and those who have families be allowed to return home and provided a sponsor to find them jobs.

That those without families be given sponsors and placed in the United States within six months.

That their rights be protected by the U.S. court system rather than by the Justice Department.

That the mentally ill inmates among the rebels be sent to hospitals for treatment.

That there be no reprisals or punishment against any who took part in the takeover.

In return, the Cuban spokesman said that after an agreement was signed on national television, they would release the hostages and promise not to sue the U.S. government or any government official. "It is our final and joint decision not to deliver any hostages except for the release of any medically approved ill hostage," the spokesman said.

However, apparently ad-libbing later, the spokesman sought to assure hostage families that their loved ones were unharmed. "All hostages are in good condition," he said. "All Cubans are in good condition. We have no problem over here."

In the hostages' broadcast, a man who identified himself as corrections officer Julio Piniero said, "Let's keep the dialogue going. They want their liberty and I think that under the situation they've been under over the past few years, we should give them what would be fair to them as they've been to us here under these conditions."

Earlier, Justice Department sources said on-the-scene negotiators were under orders to promise nothing on the inmates' chief demand to date -- to remain in the United States -- beyond the offer made Monday by Attorney General Edwin Meese III.

Negotiators have latitude on such matters as disciplinary action involving the takeover.

A Justice Department official said a near-agreement Thursday night to release as many as 50 hostages fell apart when inmates became suspicious that the detainees both here and in Oakdale had been led to believe that the other group was about to settle.

"They were requesting that a direct phone line from Atlanta to Oakdale be installed," the official said. The request was denied, and the Oakdale detainees decided independently not to sign an agreement to end the takeover there.

Three more inmates surrendered to authorities today, including one whose foot had been wounded in a knife fight. A total of 272 Cuban inmates and 175 American inmates have surrendered since the takeover, leaving 1,222 Cubans and 20 Americans in the prison.

Authorities said they did not know why the 20 U.S. citizens remained behind and that none of them had any contact with prison officials.

Water to the prison was cut off Friday. The tactic was partly symbolic because the inmates apparently have some remaining water and enough food to last "several weeks," Stewart said.

Stewart had signaled a tougher line that day, saying that officials were frustrated and were taking a "firmer posture" in their dealings with the detainees,

In a Spanish-language two-way-radio transmission early in the day, an inmate was heard to say, "Hospital to Control, they promised me in the kitchen they were going to send me two tanks of water, but they haven't."

Although there were indications that the Cubans continued to be split into factions, there were also indications that they had organized more tightly, as evidenced by the central radio control base and the addition of a public address system inside one of the prison buildings.

The first broadcast of the inmates' demands evidently was precipitated by three relatives of the inmates, who made an appeal on a twice-weekly Spanish language program on WRFG-FM here.

"Three of us went to the station and we said that we could hear them out here, and they should send messages to us," said Josefia Diaz, 54, whose husband has been in the Atlanta prison for the last 18 months.