Pope John Paul failed to appear at a midday Easter Monday blessing that traditionally marks the end of papal Holy Week celebrations, but there was no immediate indication that the Pontiff's health had worsened.
Although the Vatican had never confirmed this year's event, expectant crowds nonetheless filled St Peter's Square, chanting the Pope's name and hoping for a glimpse of the ailing Roman Catholic leader.
However, the Pope's windows remained firmly shuttered and after waiting more than an hour in the huge, drafty square, many of the pilgrims reluctantly started to drift away.
It was the first time during his 26-year papacy that John Paul had failed to appear at 12.00 a.m. on Easter Monday for the brief blessing.
"I'm not aware of any worsening of the Pope's health today. I think the doctors have advised him to rest after the activities of the past few days," a Vatican source said.
The 84-year-old Pope appeared at his window to bless the faithful on Easter Sunday but he failed in his attempt to speak, raising fears that his health was failing a month after undergoing surgery to ease a breathing crisis.
Earlier today, Vatican television cancelled plans for a midday live broadcast from St Peter's Square, but its television cameras continued to focus on the papal apartments suggesting the frail Pontiff might yet appear.
The Vatican made no official comment. The Pope's obvious suffering on Sunday cast a cloud over the most important day in the Church's liturgical calendar, with many pilgrims weeping openly as he failed to address them. Aides brought a microphone to the Pope's mouth, and although he made a few sounds he was unable to pronounce any words.
Aides then removed the microphone and the Pontiff gently tapped his lectern in a sign of resignation and frustration. The Pope has spent two spells in hospital this year following breathing crises and underwent a tracheotomy to help air flow more freely into his lungs.
The Pope, who also has Parkinson's disease, still has a tube in his throat to help him breathe. Vatican sources have said his recovery from the February 24th surgery was going slower than they had hoped. There is no indication when he might be able to resume normal activities.