HAVANA -- Pope John Paul II asked President Fidel Castro on Thursday to free some prisoners, including political activists, just hours after the pontiff blasted the breakdown of family values in Cuba and urged a return of Roman Catholic schools.

The Vatican announced the request after a private 40-minute meeting between the 77-year-old pontiff and the 71-year-old president, which took place in the inner sanctum of the ruling Communist Party, Havana's Palace of the Revolution.

Vatican spokesman Joaquin Navarro-Valls said Cuban authorities, ``taking into consideration the high moral authority of those making the request and the humanitarian character of the request, received it with interest.''

Navarro Valls said a list containing the names of an undisclosed number of prisoners was transmitted to Cuban Vice President Carlos Lage, in the pope's name, by Cardinal Angelo Sodano, the Vatican secretary of state.

In a press conference shortly after John Paul and Castro met, Navarro Valls carefully avoided political overtones in revealing that ``some prisoners'' in Cuba had written the pontiff asking that he relay their requests for clemency to Castro.

The prisoners range from ``prisoners of conscience'' to ailing inmates.

Cuba has about 500 political prisoners, human rights activist Elizardo Sanchez said this week, although Amnesty International says the number is slightly higher and anti-Castro dissidents put it much higher, saying there are several thousand political prisoners.

A beaming and solicitous Castro escorted the pope on a tour of the building that holds the president's office and the party's Central Committee. Castro introduced John Paul to senior government and Communist Party officials and, according to Vatican officials, to his brothers Raul and Ramon, and two of his sisters -- Angelita and Agustina.

Castro gave John Paul an antique book on the Rev. Felix Varela, a 19th Century Cuban priest the pope is expected to put on the road to sainthood later in his five-day visit. The pontiff gave Castro a framed picture of Jesus.

There was no immediate report on what was said during the closed-door talk between the famously anti-Communist pope and the leader of the last Marxist-ruled nation in the Western Hemisphere.

John Paul showed earlier Thursday, however, that he is willing to speak bluntly of what he considers Cuba's failings as well as its successes.

Preaching to more than 100,000 people gathered at a sports complex in the provincial capital of Santa Clara, 125 miles east of Havana, John Paul expressed criticism of a kind no outsider had made in Cuba in 39 years of Castro rule, his words softened only slightly by their pastoral tone.

``The social situation experienced in this beloved country has created a few difficulties for family stability: for example, material scarcities -- as when wages are not sufficient or have a very limited buying power -- dissatisfaction for ideological reasons, the attraction of the consumer society,'' the pope said in a homily he delivered in the first Mass televised inside Cuba since the early 1960s.

It was, indeed, a day of surprises for many Cubans.

``Do not be afraid,'' he said from an altar covered with a thatched roof, styled after a traditional Cuban bohio. ``Open your families and schools to the values of the Gospel of Jesus Christ, which are never a threat to any social project.''

When it comes to schools, ``parents . . . should be able to choose'' Catholic schools, the pope declared, without specifically noting that Castro seized and shut down more than 400 Catholic schools before he declared Cuba officially atheist in 1962.

The Cuban system that forces virtually all high school students to leave home and enroll in rural schools results, he said, in ``promiscuous behavior, loss of ethical values, coarseness, premarital sexual relations at an early age.''

Quotes Jose Marti

John Paul got the strongest ovation when he left his prepared text to quote from a work by Cuban independence hero Jose Marti.

``In the process of building a future, with everyone and for everyone, the family, the school and the church should form an educative community where the sons of Cuba can grow in humanity,'' the pontiff said.

``Don't wait for everything to be given to you,'' the pope added. ``Assume your education mission, searching for and creating the means adequate for civil society . . . Do not be afraid.''

Turning to abortion, which ends nearly half of all pregnancies in Cuba, the pope said it ``is always, in addition to being an abominable crime, a senseless impoverishment of the person and society itself.''

In a reference to Cuban exiles, John Paul said that politics, economic crisis and government policies have long created a wave of emigration ``that has separated entire families and seeded pain in a considerable part of the population.''

A remarkable scene

Outbreaks of applause interrupted his sermon four times but overall the audience's reaction was generally subdued.

Still, it was a remarkable scene after decades of repression of the church.

``I never thought I'd be seeing this,'' a senior Cuban journalist said as he watched a live broadcast of the papal Mass, transmitted across the island in a last-minute concession by the Cuban government.

The Vatican had insisted for months that state-run television should broadcast all of the pope's ceremonies throughout Cuba, but until Thursday the government had insisted it would provide only local coverage for all but the pope's final Mass in Havana on Sunday.

The crowd appeared to include a mix of young and old, black and white, men and women, and faithful Catholics side by side with revolutionaries who were told by Castro last week to attend the papal events as a sign of respect for the visitor. Some clearly were bewildered by the pope's words and uncertain about how to react.

One man in an ill-fitting blue suit -- the trademark of Communist Party functionaries -- was seen beginning to stand to applaud, then sitting and finally standing again but not clapping.

A `moral crisis'

But the pope's words echoed among many Cubans who have long talked about a ``moral crisis'' on the island because of policies and tenets of the Communist government.

A majority of couples in Cuba today are not married and merely live together.

``There are many sporadic couplings. You know, `If I like it, I'll stay. If I don't, I'll change,' '' said the Rev. Manuel Jimenez, parish priest at the Sacred Heart Church in Havana's Lawton district.

About 23 percent of all official marriages in 1995 ended in divorce. Promiscuity is common, especially among young people, who have few diversions. In 1990, only 34 percent of all babies were born to married women.

Blessing the children

The day began on a tender note for the pontiff, who, apparently suffering from jet lag, got up earlier than expected and surprised a children's chorus that was to sing a wake-up serenade outside the Vatican ambassador's residence in Havana.

John Paul came out fully dressed and kissed and blessed the children. They were so touched by his bearing and kindness that many started to cry, said one nun who has been helping with logistics at the papal nuncio's residence.

Security for the papal events continued to be low key, with large numbers of plainclothes security agents deployed discreetly in the Santa Clara crowd.

Before Mass started, Cuban government officials took the microphones at the sports field and explained proper behavior over a loudspeaker to many people who had never been to Mass.

In a city of 210,000 people, where the remains of revolutionary leader Ernesto ``Che'' Guevara were buried only last year, huge crowds of flag-waving Cubans lined the papal motorcade route from the airport to the sports field.

And many chanted a version of a Castro-era slogan that Christians have appropriated for the papal visit: ``John Paul II, the people are with you.''