A second publicized attempt by communist authorities to pull crucifixes off the walls of a state school has renewed strains between the government and the Roman Catholic Church over the rights of Poles to display religious emblems in state institutions.

The latest conflict began 11 days ago when students at a vocational school complex in Wloszczowa, a small town about 150 miles south of Warsaw, hung crosses in 17 classrooms and in a school shop. The principal ordered the crucifixes removed the same day, moving students to stage a sit-in strike that is continuing and has the support of area priests.

A conference of Polish bishops meeting last week condemned the government's action in a statement which called the banning of crosses in schools "socially harmful" and expressed the hope that "basic human rights will be respected in our country." Archbishop Bronislaw Dabrowski, secretary of the episcopate, has sent a letter of protest to the government backing the students' request to rehang the crucifixes.

But reaffirming the government's stand, spokesman Jerzy Urban today said that religious symbols in schools violate the secular character of those schools as stipulated in a 1961 law on education. He said the government's position is "firm and unchanged," and he blamed two local priests who have joined the sit-in for "firing up fanatical emotions among the youth."

Church officials have acknowledged that the government has the legal right to ban what it wants from state schools, offices and factories, but they have urged communist officials to show sensitivity to Catholic sentiment in this overwhelmingly Roman Catholic country.

The current controversy is a repeat of a church-state clash in March involving an agricultural high school in the town of Mietne, about 40 miles southeast of Warsaw. After a month of intense high-level negotiations then between communist and Catholic authorities, a compromise was reached allowing students to put up a single cross in a reading room at the school. In Wloszczowa so far, students have rejected a similar compromise offer from the authorities, according to an official press report.

Complicating efforts to resolve the flare-up this time is lingering bitterness in the church hierarchy and among Poles over the murder in October of the Rev. Jerzy Popieluszko, a popular Warsaw priest who championed the cause of the outlawed Solidarity trade union. An indictment formally charging three Polish secret police officers with the October murder, and charging their superior, a colonel, with aiding and abetting them, was sent to a court in Torun today.

"Our society, living in tension and the expectation of justice, has not yet calmed down after this incredible crime," the bishops said in their statement last week. "Irresponsible persons already cause new disturbances and tensions." Although not citing Wloszczowa by name, the bishops objected to "cases of crosses being removed from places where believers learn and work," saying these moves "sometimes look like a provocation. We think such deeds are socially harmful."

In an unusual action, the government itself was the first to name Wloszczowa as the scene of protest. On Saturday, a day after the bishops' statement, the state-controlled Polish Press Agency (PAP) carried an English-language translation of a lengthy article by a communist paper in Kielce, near Wloszczowa, giving a detailed and apparently accurate account of the conflict.

Some Poles and western observers suspect the government wanted to focus public attention on the crucifix dispute and away from the more disturbing implications and unanswered questions of the Popieluszko case. But others here see the PAP report as an attempt merely to preempt surprise disclosure in the western press of the strike by offering an official version of events containing the government's justification for stripping down the crucifixes.

Correspondents for American and West European wire agencies who tried during the weekend to reach Wloszczowa by car were detained by police on the outskirts of town, questioned at a militia station, then escorted out of the vicinity. Urban today said the police acted to maintain order, adding that "very often" foreign journalists have "the aim of interfering in events in Poland and creating them."

Reports from some of Wloszczowa's 12,000 residents say that several hundred of the school's 700 students are participating in the sit-in. Corridors and classrooms are said to be packed with sleeping bags and blankets, school halls have been decorated with religious emblems, and the students have been singing religious songs to pass the time. Food is being supplied by area residents.

While classes at the school remain suspended, they resumed today for final-year students in makeshift classrooms at a cultural building in Wloszczowa, Urban said.

Urban urged the church to respect the separation of church and state spelled out in the Polish constitution -- a principle, he said, which serves as "a foundation of the church's independence" by protecting it against state interference.

Although church officials claim that posting emblems on school walls does not change the secular character of schools, the government says it does. And, Urban stressed, the final judgment on such matters rests with the state.