VATICAN CITY -- Pressing his hand to his head and pounding a lectern in apparent frustration, Pope John Paul II made a brief but silent appearance at his apartment window after missing his first Palm Sunday Mass in 26 years as pontiff.
The frail John Paul did not speak and appeared irritated by his difficulty in responding to an adoring crowd of tens of thousands of pilgrims in St. Peter's Square.
The crowd in the sun-drenched plaza had swelled in expectation that John Paul, convalescing at the Vatican after throat surgery last month to help him breathe, would participate in the Palm Sunday rite ushering in Holy Week.
Pilgrims cheered as the pope appeared at the third-floor window, decorated with a braided palm frond and the crimson papal banner, and waved an olive branch.
He appeared for no more than a minute. He put his hand on his face and pounded the lectern once just before the white curtains at his window were drawn closed.
Vatican television did not zoom in on John Paul as it has in his past window appearances at the Vatican and earlier at the Rome hospital that treated him for a breathing crisis.
"With great joy I salute you," the pope said earlier in remarks that included a special welcome for young people and were read by an archbishop.
It was his third public appearance since he was discharged from the hospital a week ago, one of them by video hookup Thursday when he looked gaunt and made a similar gesture of covering his face as if he were in pain.
The use of television and video has become more important to John Paul's papacy as he is slowed by his ailments and the Vatican seeks to reassure the faithful with his image. Pilgrims in St. Peter's Square Sunday strained to see him high in his window or followed his appearance on giant TV screens erected in the square.
Cardinal Camillo Ruini, the pope's vicar for Rome, led Sunday's service in place of John Paul, who Vatican officials said had planned to follow the Mass on television.
The Mass included a special prayer for the 84-year-old pontiff, calling him "our beloved father" and asking that he continue in his "service up to the gift of life."
"I came to see him," said Roswita Ginglas, a German pilgrim who, like many here, had tears in her eyes when the pope appeared. The crowd held up olive branches when John Paul came into view.
"You could feel his presence in the whole square, even if he didn't speak," said Pauline Everden, an Anglican tourist from England.
John Paul, who was discharged from the hospital last Sunday, has long presided over the ceremony marking the start of the most important week in the Roman Catholic liturgical year. For years, it has been one of this pope's favorite appointments.
Potted olive trees surrounded the obelisk at the center of the square for the Mass, which commemorates Christ's triumphant entry into Jerusalem.
In his homily, Ruini spoke of Christ's ordeal and the "drama and mystery" of suffering and its meaning for humanity. The Italian cardinal said Christ's cross brings "new energies" and "shines with special clarity on the weary face of the Holy Father."
Andrea Glatz, an Austrian university student, said the pope "is like a magnet for young people, even though he's old and sick."
Many young people were in the crowd for the Mass, part of the church's World Youth Day activities that culminates in mid-August with a celebration in Germany -- the pope's only scheduled foreign trip this year.
John Paul mentioned the event in his message read by Archbishop Leonardo Sandri of Argentina, who has become the pope's public voice since his latest hospitalizations. But he did not say whether he would attend.
The pope is convalescing at the Vatican after Feb. 24 throat surgery to insert a tube in his windpipe and ease his second breathing crisis in less than a month.
Since the operation, John Paul has only spoken twice publicly, each time just a few sentences delivered in a raspy voice. He also suffers from Parkinson's disease, which affects muscle control and makes it difficult for him to speak clearly.
Because of frail health, the pope already had scaled back some Holy Week traditions in recent years. For example, he would sit and pray while observing the Way of the Cross procession at the Colosseum on Good Friday evening, no longer carrying the cross.
Sunday kicked off a busy week of events culminating in a week with Easter Sunday. The pope has designated other prelates to stand in for him, and the Vatican says his only commitment is his Easter blessing.
But he has not named a prelate to lead the Good Friday procession, and the Vatican says he may be considering taking part in some way.