A shadowy international group claiming links with dissidents in Saudi Arabia is stepping up a propaganda campaign among the 13,000 Saudi students in the United States.

The CIA is concerned about the new group, and has notified the FBI of its interest, FBI sources say. The group is a novel element in U.S. official forebodings about the stability of the Saudi regime, and it has already led to pressimistic guesses that the monarchy may collapse within two to five years.

When Iranian students started to campaign against the now-deposed shah of Iran, their activities were ignored for a long time. But the Saudi pamphleteers already find themselves in an anxious limelight.

Calling themselves Sout al-Taliah -- "Voice of the Vanguard" -- the group was founded in 1973, its supporters say, but has been dormant for years. Now, from bases in San Francisco and Denver, it is distributing literature across the United States, in Arabic and in glossy English-language booklets.

One of Sout-al-Taliah's spokesmen, who would identify himself only as "Tariq," said in a telephone interview from Denver last week, "Both the CIA and the FBI should not be concerned with our activities.

"We feel some pressure. We think it should stop. If not, the American establishment will become involved with the Saudi intelligence as they did with Savak [the secret police] of the shah."

Sout al-Taliah claims to be part of a network of left-wing nationalists, with a collective leadership based abroad and financial support from Saudi students in the United States.

The Saudi students are "all getting about $1,000 a month and can afford to support us," according to Tariq, the only member of the Denver group, he says, who can speak English.

The group deflects questions about its precise strength, identity and backers, although members deny any relationship with the Palestinians, the Libyans or the Iranians.

They use the language of nationalism and human rights rather than that of Islamic fundamentalism, attacking compulsory mosque attendance and calling for a democratic presidential system to replace the ruling royal family.

In their English-language booklet, "Pillars of the Saudi Regime" published this month without any identification other than a San Francisco Post Office box number, the group attacks the Saudi Prohibitions on dress and conduct. Restrictions have been tightened since last November's uprising at the Grand Mosque in Mecca by traditionalist dissidents.

"Practically everything is prohibited in Saudi Arabia," group says, citing moustaches: "If you shave your beard and grow your moustache, you incur the wrath of the regime."

The regime's religious organization imposes on-the-spot fines for such conduct, Sout al-Taliah says, and is more backward than 14th century Europe. c

While members of the Saudi ruling family have complained bitterly about U.S. press coverage in recent months, this newly active, although nervously anonymous group, says the opposite. Sout al-Taliah claims the U.S. government is so concerned about Saudi sensitivity that it tries to hush up the facts.

The group maintains that the Saudi royal family, under 67-year-old King Khalid, is autocratic, backward and "wallowing in corruption."

Saudi spokesmen in Washington declined comment on the group.