a television journalist, a librarian, a diplomat, a Presbyterian minister and a Catholic priest -- have been kidnaped at gunpoint on the streets of Moslem-dominated West Beirut in the past year and disappeared.

Until the past week, they seemed to have been lost in the chaos of a region where, as one friend put it, "there are no rules, no demands, just silence."

But on Friday and Monday anonymous callers claiming to represent the terrorist group, Islamic Jihad (Holy War), broke the silence, telling news services in Beirut that the U.S. citizens will be tried as Central Intelligence Agency spies and given "the punishment they deserve."

"This raises the stakes and introduces a new element of graveness," a State Department official said.

"That's not good news for the family," said John Mihclich, of Joliet, Ill., a nephew of the priest captured a week ago, the Rev. Martin Lawrence Jenco. "It's a little frightening . . . ."

"It's getting very hard, and it's getting very scary, with this latest news," said Clare Moss, stepdaughter of the captive TV journalist, Cable News Network's bureau chief Jeremy Levin.

For these hostages and their families there have been no coast-to-coast sprouting of yellow ribbons, no chanting mobs, no nightly television specials, no pronouncements from top U.S. officials about saving them at all cost. There have been none of the political atmospherics that surrounded the Iranian hostages, who were released dramatically at the hour of Ronald Reagan's first inauguration four years ago.

The captured Americans, in addition to Levin and Jenco, are:

* William Buckley, a political officer at the U.S. embassy.

* The Rev. Benjamin Wier, a Presbyterian minister.

* Peter Kilburn, a librarian at the American University of Beirut.

The administration's policy, according to a State Department spokesman, is that "we don't feel it does any good for their safety to talk too much publicly about what we're doing . . . . We are doing whatever we can." And so far, few at any point along the political spectrum seem sure this isn't the best policy.

"It is the advice of everyone from the secretary of state to the old CIA types that the more you talk about them, the greater value they will have as bargaining chips," said Ed Turner, of Atlanta, the Cable News Network executive vice president who gave Levin his Beirut assignment.

Turner spent two months in Beirut trying to help Levin after he was kidnaped on March 7 and, Turner said, made contact with 47 political factions.

"You can't just go into a bar and say I'll give you 10 grand to let Levin go," Turner said. ". . . You're dealing with shadows and mist in a land where there is no law . . . . The most nerve-racking and frustrating part of it is that you don't know what to do, what levers to hit."

"We don't want them the administration to go pressing into things prematurely," said Jeff Jenco, another nephew of the priest. "We don't want to jump to conclusions or anything about them not doing a good job . . . . We want to keep an open mind."

Some family members say they felt torn between a desire to "do something," to "speak out" to help their captured kin, and the suspicion that a blitz of publicity was harmful to the Iranian hostages and would be in this case, too.

Lucille Levin, wife of the kidnaped bureau chief, who has developed into a semiofficial spokesman for the families, decided in September to publicize the issue but in a manner that emphasizes compassion for the "anguished people" of the Middle East. She did this, she said in an interview, after she became frustrated that the subject had "not even come up" during the 1984 presidential campaign. "Silence doesn't solve anything," she said.

Levin, who lives in the District, and Carol Weir, wife of the Presbyterian minister captured last May, have appeared several times on NBC's "Today" show. They are calling for a more conciliatory, evenhanded U.S. policy toward the Middle East; they praise the approach taken by Jesse L. Jackson.

Jackson has raised the possibility of a trip to Syria to negotiate toward the release of the five Americans, who reportedly may be held captive in Syrian-controlled territory.

But the women generally have steered clear of direct criticism of the administration, and they give high praise to the work of some State Department specialists.

Levin expressed continuing frustration that U.S. newspapers and television have given little attention to the issue. Last fall, she asked in an interview, "Why haven't these hostages been talked about? Why has it been left to stand that Reagan said there will never be hostages taken again? Are we bored with hostages? Is it now a ho-hum thing, or does America care any more?"

Just before Christmas, former president Jimmy Carter accused the White House of trying to sweep the issue under the rug. "The Reagan administration's policy has been quite different from mine," he said, referring to his handling of the Iranian hostage issue in 1979 and 1980. "Basically it's [Reagan's policy] to ignore any American hostages that have been taken and to conceal the fact that they are being held."

Most Democratic congressmen, however, have been restrained in their comments.

The Democratic members "have been very careful about what's been said in public . . . . I don't think there's a lot you can criticize here," said a Democratic aide to the House Foreign Affairs Committee.

The terrorist groups involved "love publicity, so you can argue that denying them that publicity is good. On the other hand, it doesn't get your people out," the aide said.

Jenco, captured a week ago, was head of the U.S.-based Catholic Relief Services office in Beirut. He is said to suffer from a heart condition.

His family and friends have received letters he wrote just before his capture. In them, he spoke of his fear of death, of the "constant, constant violence" that surrounded him and of the bone-chilling cold:

"As I began midnight Mass, the shelling began . . . . The other night, I had to sleep on the floor of the dining room of my apartment. I had to figure out which room was safest. I am not sure there is any place that is safe . . . .

"A candle is not my idea of central heat. We have six hours of electricity a day."

Referring to other kidnapings in the region, he wrote, "To walk a block, for me, is an anxiety trip. . . . I'm sure my heart couldn't take that kind of stress."

Kilburn, the librarian and a native of San Francisco, has been missing since Dec. 3. Kilburn's physician was quoted in an American University statement as saying Kilburn suffers from heart and artery ailments, hypertension and other problems and is in "urgent need of medicaments."

He had worked at the university in Beirut for 20 years.

Weir, the Presbyterian minister, was on his way to work when he was kidnaped in May. His wife continues to live in Beirut.

Buckley, the only diplomat in the group, was abducted March 16 in front of his West Beirut apartment building as he left for work. Witnesses said he tried to escape, but two carloads of gunmen blocked his auto.

Levin had been seized a week earlier, sometime after his wife had left for the day to attend classes at the Near East School of Theology.

"That was 315 days ago," Lucille Levin said this week. "Carol Weir is very discouraged . . . . But I don't feel that way. My Arab friends are helping. The compassion I have received from Arab friends has been overwhelming. I am constantly reassured."

Informed observers said that recent attacks, kidnapings and other violent acts have been fostered by a broad pro-Iranian regional terrorist movement geared to spreading Islamic revolution and gutting U.S. influence in the Middle East, not simply by political turmoil in Lebanon.

Malcolm Kerr, president of the American University of Beirut, a prominent scholar and a symbol of American cultural influence there, was killed Jan. 18, 1984, gunned down outside his campus office. His predecessor, David Dodge, was kidnaped and held for a year by Moslem extremists. An engineering professor at the university, Frank Regier, was kidnaped Feb. 10 and freed two months later by Shiite Moslem militiamen.

The U.S. government repeatedly has urged all U.S. citizens without urgent business in Lebanon to get out. Thousands have heeded the call. By year's end, perhaps a couple of hundred native Americans remained in Beirut, according to rough official estimates.

Many of them are media employes or teachers concentrated at the American University of Beirut and other schools.

Last Friday, a caller claiming to represent Islamic Jihad stated for the first time that the group was holding the five Americans and would release them unharmed if all Americans left Lebanon. A State Department spokesman responded that the United States intends to keep some Americans in Lebanon, apparently prompting Monday's threat to try the captives as spies.

State Department spokesman Alan Romberg said that although there is no evidence the second call was authentic, officials are treating the threat as "grave and serious." He called the charges that the five "used journalism, education and religion as a cover" for subversive activities "patently absurd."

If the Monday call were authentic, said Levin, it is a sign the kidnapers "are probably feeling extreme frustration. This [issue] isn't news here. It isn't even mentioned."