Pope John Paul II's fragile health has suffered another setback. He is now being treated for a high fever caused by a urinary tract infection.

Reports of the Pope's deteriorating health trickled out of Rome earlier Thursday, prompting speculation he had taken a sudden and drastic turn for the worse.

Shortly after Italian news agencies reported that a sudden drop in the pontiff's blood pressure had prompted doctors to intervene, the Vatican issued an unusually detailed briefing.

"The Holy Father today was struck by a high-fever caused by a confirmed infection of the urinary tract," Vatican spokesperson Joaquin Navarro-Valls said.

The condition was being treated with the "appropriate antibiotic therapy," he added. "The clinical situation is being closely watched by the Vatican medical team treating him."

Indeed, the light at the nursing station outside the pope's apartment was reported still on well past the papal bedtime Thursday night.

Overnight in Rome, Italian news reported the Pope's condition as stable and responding well to the antibiotic treatment.

And in a report that fuelled contradictory speculation, ANSA said an emergency room chief at the Rome hospital where the Pope stayed twice last month said there were no immediate plans to admit him a third time.

For some, the report suggests the Pope is healthy enough not to need hospitalization, while for others it suggests he may be too weak to move.

Whatever the case, a crowd of hundreds had gathered to hold vigil beneath the Pope's apartment window overlooking St. Peter's Square.

"There's nothing we can do but pray. We're all upset," Agriculture Minister Giovanni Alemanno told The Associated Press as he milled among the swelling crowd.

Last Rites

The Vatican offered no comment Thursday on reports the ailing 84-year-old pontiff had been given the last rites, or holy sacrament reserved for the infirm.

If true, this would not be the first time the Pope has been so anointed. In 1981, after a failed attempt on his life, he was also given the last rites.

Recalling those days after the Pope was shot, veteran reporter Larry Stout said many were then saying he would never survive.

"Well, he has lasted," Stout said. "And since that time he has probably circled the Earth at least once."

Watching developments from Toronto, Father Thomas Lynch said that love of reaching out to the faithful is one of the Pope's defining characteristics.

"In terms of sitting behind a desk, that was never his strong point. He delegated that to who he considered to be capable people and he went out to meet people."

In the process, John Paul II kissed the ground in 129 countries, becoming in the process the most traveled, public pope in the history of the Church.

Worsening Health

The Pope has had to slow down considerably in recent months, however, as a series of medical setbacks have forced him to curtail his normally packed schedule.

On Wednesday, the Vatican underscored the seriousness of his condition when it confirmed the Pope was being fed through a tube.

Just hours after the pontiff made a brief silent appearance at his apartment window overlooking St. Peter's Square, Navarro-Valls said doctors had inserted a nasal-gastric feeding tube.

It would boost the Pope's strength and aid his "slow and progressive" convalescence, the Vatican spokesperson told reporters.

There are reports difficulty swallowing have contributed to the Pope -- who also suffers from Parkinson's disease as well as crippling knee and hip ailments -- losing 19 kilograms since undergoing a tracheotomy to ease his breathing on Feb. 24.

That was the second time he was admitted to Rome's Gemelli hospital in a month.

Throughout his recovery, the Pope has made repeated efforts to maintain at least part of his public schedule.

Last week, for the first time in his 26-year papacy, the frail pope scaled down Holy Week appearances because of his ailments.

He tried, but failed Sunday to give a blessing to the crowd gathered for Easter Sunday Mass.

The last time he spoke to the public was March 13, shortly before he was discharged from hospital for the second time.

With reports from CTV News