RIGA, U.S.S.R. -- The fear and violence that have gripped Latvia for weeks have many names but just one face: the Black Berets.

An elite band of Soviet paramilitary troops, the Black Berets maintain perhaps the highest profile of any party to the struggle between Latvia and the Kremlin. Black Beret troops staged a nighttime assault on the Latvian Interior Ministry a month ago that was widely viewed as a coup attempt.

The attack failed to topple Latvia's pro-independence government, but it left four people dead and cast a shadow of fear over the republic that is no less palpable or intimidating than the extra clips of ammunition strapped to the Kalashnikov assault rifle of an officer named Andrei.

Andrei is a Black Beret, a major who shot his way into the Interior Ministry building. "Our duty is to uphold law and order. Neither I nor my unit plans to leave" Latvia, he said recently, slouching at his desk in the unit's barracks, which is protected by coils of barbed wire, an armored personnel carrier, jittery troops and a sign that states the obvious: "Forbidden Zone."

Andrei, 42, who refused to give his last name, spoke with a tired voice, like someone who had slept only sporadically for many weeks. As he talked about how Russians allegedly face Nazi-like persecution in Latvia, his pale eyes occasionally rested on the items cast about his colorless office -- a flak jacket, a walkie-talkie, a helmet, a bayonet, stacks of ammunition, a calendar featuring a half-naked woman.

"Under the cover of a fight for democracy in the Baltics, fascism is reviving," he said.

The Black Berets -- who are also known by their Russian-language acronym, OMON -- are under the command of the Soviet Interior Ministry in Moscow, and some of its members have worked independently for the Latvian Communist Party.

Latvians describe them as a band of political storm troopers controlled by Soviet hard-liners, but the Black Berets deny consistent reports of almost daily violent harassment, including beatings and shootings.

Whether the Black Berets acted under orders from a higher authority Jan. 20 when they attacked the Latvian Interior Ministry -- which is the headquarters of the republic's police force and is independent of the Soviet Interior Ministry -- remains unproven though widely believed. Andrei denies that his outfit was attempting a coup, claiming that the Black Berets assaulted the ministry because some of them were fired on by pro-independence "terrorist units" and needed to take refuge in the ministry building.

Information being gathered by an official investigation and accounts of witnesses do not support his version of events, according to Latvian officials. They say that the Black Berets had set up a machine-gun nest opposite the ministry, that the street in front of the ministry was blocked off by Black Beret vehicles and that a flare was fired just before the attack, presumably as a signal to begin.

Because Latvians make up only 52 percent of the republic's population, their government is more fragile than the similarly independence-minded leaderships in neighboring Lithuania and Estonia. Perhaps the weakest link in the Baltic states' bid for freedom, Latvia seems to face a complex destabilization campaign in which the Black Berets may be just the most obvious element.

Officials and journalists believe several forces, perhaps working independently of each other, may be trying to overturn the breakaway government. The Soviet military and its intelligence agency, the GRU, are mentioned frequently, as are pro-Moscow factions in the local branch of the Soviet KGB security police, the republic's 5,000-man police force and the Latvian Communist Party.

"I am more than convinced that this attempt at a coup will be attempted again," said Latvian Interior Minister Aloicz Vaznis. "When or how, I cannot say. But it will happen." On the wall above Vaznis's desk are several good reasons for fear: three bullet holes from the Black Berets' attack. Vaznis, whose nerves have been hardened by 16 years as head of the ministry's criminal division, rose out of his chair to point out a thimble-sized bullet hole in the window next to his desk. "That one was for me," he said. His finger was trembling.

Vaznis and other Latvians contend that their principal foe is Alfreds Rubiks, general secretary of the hard-line Latvian Communist Party. Rubiks, described by many Latvians as having a piercing gaze and chilling smile, is chairman of the pro-Moscow committee that many thought was heralding an imminent coup when it declared it was seizing power two days before the Black Beret raid. Unlike many Communist leaders in the Baltics, Rubiks is regarded as highly intelligent and clever.

In an interview at party Central Committee headquarters, Rubiks denied any link to the attack, and he claimed his National Salvation Committee had no contact or orders from officials in Moscow. He refused to explain how the group, whose full membership is not known, planned to take power.

"Why speculate about things that did not happen?" he asked with a smile.

However, Rubiks acknowledged that the party paid the Black Berets last year to guard the Central Committee building and other party property. The money -- he does not know the amount -- was funneled through a private cooperative called Viking that the Black Berets formed as a for-hire security agency.

The confusion in Latvia is personified by Edmunds Johansans. Like most Latvians, Johansans said he does not know whether Rubiks or Moscow -- or both -- were behind the Black Beret attack. He seems uncertain of whom he can trust, feels somewhat powerless and is fearful about the future.

Johansans is director of the Latvian KGB.

In an interview at his office overlooking a street that until recently was named after seminal communist theoretician Friedrich Engels, Johansans said the Black Berets "were not alone responsible. . . . People of extremist views might have been involved" in the Jan. 20 attack. He appeared to be referring to a "third force" of provocateurs that journalists and officials here suspect worked independently of the Black Berets.

Two of the people killed in the attack were policemen guarding the Interior Ministry, but the other two were apparent bystanders watching from a park about 200 yards away. The Black Berets deny killing anyone and say their fire was only aimed at the building, not at the park.

Investigators are looking into witnesses' reports of shots coming from behind the felled bystanders and reports of suspicious people lurking there. Questions have been raised as to whether someone from the "third force" was in the park, firing at bystanders, perhaps to increase bloodshed and inflame passions, giving Moscow an excuse to impose presidential rule or martial law in Latvia.

It is a measure of the political chaos and shadowy power struggle that the local KGB chief cannot answer these questions -- and reportedly cannot trust his own men. Officials here say they think Johansans, who says he reports daily to the KGB director in Moscow and to the Latvian government, is trying to be neutral. But an anti-independence KGB faction may be skirting him and taking direct orders from Moscow -- or Moscow may have sent its own people to Latvia, according to officials and journalists here.

More open is the split taking place in the Latvian militia. The majority of the republic's 5,000 police are Russians who have shown themselves sympathetic to Communist Party claims that independence will lead to discrimination against Russians. At a Jan. 28 meeting, shouts and insults from leaders of the Russian militia interrupted speeches by the republic's top officials. The militia leaders loudly applauded when a hard-line opponent of independence spoke.

At least 11 policemen have joined the Black Berets, according to Interior Minister Vaznis. He admitted that one of his main tasks is to avoid a split in which the majority of his police align with a pro-Moscow prosecutor's office and enforce the Soviet laws that were repudiated last year when Latvia asserted independence from the Soviet Union.That would be a major step toward Moscow regaining control over Latvia.

Meanwhile, the Black Berets remain at their barracks on an unmarked dirt road about 10 miles from the center of Riga. Morale seems good, bolstered by the 30 to 40 letters, mostly unsigned, that are tacked onto a bulletin board. One anonymous message urges: "Fellows, stay strong. We are with you." Another, a poem sent by a 12-year-old boy, ends on an upbeat note:

"Because OMON does not want war

"OMON is the friend of the Soviet state."