Vienna — * Four of 20 Franciscan monks scooped up in Eastertide police raids in Prague and several other Czechoslovak cities are held and charged with ''illegal religious activity.''
* The Czech Communist Party newspaper Rude Pravo prints a scornful attack on an extravagant new wave of punk-rock music among the young.
These recent news items might seem unrelated. But both are closely linked to a major problem of special concern for some time to an economically beleaguered Prague regime - the apparent ever-spreading disaffection among the nation's youth.
The Franciscans and other small or relatively loosely organized religious groups have been a special target of the campaign against religion in recent years, often because of their identification with the young.
As on previous such occasions, books and papers were confiscated from homes the police entered Palm Sunday. The Catholic news agency here reported the police did not have search warrants. (One young priest who challenged their right, the agency said, was handcuffed to a radiator while his room was searched.)
''Illegal'' priestly activity for such groups as the Franciscans usually means working in a considerable ''underground'' church developed in recent years. This church continues strongly despite harassment and, moreover, is apparently proving particularly attractive to the young.
The Communist authorities choose to see it as a direct challenge. They allege it is part of a general Vatican endeavor under its Polish Pope to build up a ''fifth column'' dangerous to the Czechoslovak state in line with the Reagan administration's ideas of ''destabilizing'' East-bloc regimes.
Many of these clandestine clerics are young ordained priests whom the government refuses to license; others are older ones whose authorizations have been annulled. The ban is often laid on those who oppose or refuse to join the government-sponsored religious organization ''Pacem in Terris.''
Many have been jailed for defying the ban. According to church estimates, the number of imprisoned priests in Czechoslovakia at any one time has rarely fallen below 100 in recent years.
Religious instruction of children is prohibited except on church premises and requires official sanction of a formal request by both parents. It has become an act of courage for parents, for this step frequently means loss of a job.
It is, for example, impossible for an actively practicing Catholic to be a schoolteacher or, in fact, to hold any meaningful administration or managerial post; and children whose parents opt for religious instruction for them may find they are barred from higher education.
Such elements of repressive dogma in Communist rule have combined to foster a mood of deep frustration among many youths. Many react by turning toward religion or toward the kind of ''way-out'' music denounced by Rude Pravo.
''A philosophy of nihilism, marasmus (decay), and a cynical approach to life, '' the newspaper said of new groups styling themselves the ''Yellow Dogs,'' ''Sausage Wrappers,'' ''Hard Currency Allowance,'' and so on.
The paper indicated that the authorities are particularly concerned that such groups include many ''professionals'' from such preserves of the party as the Socialist Union of Youth or from the trade unions and the ranks of local government employees.
''It's not surprising,'' commented a Czech intellectual recently. ''The party has its sports and recreation clubs, but everything is so organized and so strictly performance-oriented that many youngsters want nothing of them.
''There is really nothing for the kids if they wish just to enjoy doing their own thing or just kick a ball around a football ground without feeling they have to excel or lose sleep over a result.
''A lot look to religion, partly because it is something which seems in some way forbidden, which also makes it attractive, partly because it offers to fill a gap in their lives.
''It exasperates the authorities because they see themselves rejected by youth. They are not able to fill that gap and, worse, they know it and that they still obviously haven't anything better to offer.''
A provincial party secretary reported not only that young people's interest in joining had declined by half, but that many accepted as candidate members were then withdrawing.
''They just don't realize,'' the intellectual added, ''that many youngsters are looking for more than either Marxist materialism or total consumerism, so the regime fails on both counts.''
The ''underground'' church draws especially from intellectual youth. Its Bible studies, lectures, and services conducted in the priests' own homes, with always the hazard of an abrupt police visit, have become, so to speak, a militant auxiliary to the mainstream of the Catholic Church which, for obvious reasons, works within the rules.
But the Catholic Church itself is circumscribed in many areas - with rigid limits on admissions to theological training and on religious publications. It is always liable to official interference.
Prague's leaders are among the most virulent critics of Polish events since 1980. They have sometimes seemed to think the role of the Polish church in this critical period could be emulated in Czechoslovakia. That is an unrealistic proposition. The Catholic Church there may claim half of 15 million Czechs and Slovaks as followers. But it was never a ''national'' church (like Poland's) and 30 years of Eastern Europe's most consistently aggressive atheistic campaigning have taken a heavy toll on its practicing strength.