Black smoke spewed from the makeshift chimney on the Sistine Chapel Monday, signalling that the first papal vote has been completed and no new pope was chosen.

There was some confusion when the first puffs of smoke wafting from the chimney at about 8 p.m. ET (2 p.m. EDT) appeared to be white or grey.

This prompted a Vatican Radio commentator to say, "It seems white."

But as darker smoke followed, the station proclaimed the smoke to be black, meaning the 115 voting cardinals will retire for the night and that their first conclave vote was inconclusive.

"It looks like the stove wasn't working well at first," an announcer quipped a few minutes later.

The cardinals will return to the chapel Tuesday morning where there will be two more rounds of balloting in their search to elect a successor to Pope John Paul II.

If those two rounds of voting also pass without electing a pope, there will be another two rounds in Tuesday afternoon.

To be elected, a candidate needs at least 77 votes, or a two-thirds majority.

The world had its final glimpse of the cardinals responsible for picking the next leader of the Roman Catholic Church on Monday as they will remain sequestered until a new pope is chosen.

Cameras were rolling as the red-robed cardinals, also known as the "princes of the Church," entered the Sistine Chapel, where Michelangelo's fresco of the Last Judgment will stare down on their deliberations.

After the procession, cardinals took an oath of secrecy. The first part was read out jointly by cardinals.

In it, cardinals pledge "to observe with the greatest fidelity and with all persons, clerical or lay, secrecy regarding everything that in any way relates to the election of the Roman Pontiff and regarding what occurs in the place of the election, directly or indirectly related to the results of the voting."

Each cardinal then approached a book of Gospels, with each putting his hand on the book and reading from it.

The doors to the Sistine Chapel were closed at 5:27 p.m. local time, after Archbishop Piero Marini said "Extra Omnes" (Latin for "Everyone Out").

Outside, the thousands of pilgrims who have gathered in St. Peter's Square let out a cheer.

Ratzinger has blunt message

In a morning Mass in St. Peter's Basilica, Cardinal Joseph Ratzinger urged the cardinals not to follow the fashion of the time, and to choose a pope who will defend traditional doctrine.

Ratzinger, the 78-year-old dean of the College of Cardinals, is considered the frontrunner to become pope.

"Having a clear faith, based on the creed of the church, is often labelled today as a fundamentalism," Ratzinger said in a morning homily.

"Whereas relativism, which is letting oneself be tossed and swept along by every wind of teaching, looks like the only attitude acceptable to today's standards.

"We are moving toward a dictatorship of relativism which does not recognize anything as for certain and which has as its highest goal one's own ego and one's own desires."

CTV's Tom Kennedy, reporting from Rome, said it appears as if there is a split between the cardinals -- between those who believe as Ratzinger does that the church must not change, and those who think the church should reform.

"But generally there is pressure on the cardinals to decide quickly. They do not want to leave the impression that the church is divided," Kennedy told CTV's Canada AM.

Choosing the next pope

As the cardinals gather for the secret balloting, they are faced with two choices: to choose an older cardinal who could serve as a "transitional" pope, or a younger, more dynamic cardinal from the developing world.

The selection isn't expected to take more than a week. In the last century, conclaves have not lasted more than four days. The selection of Pope John Paul II took eight ballots in three days.

In the days after Pope John Paul II's death on April, 2, Ratzinger's name has come up as top on the list of contenders. He is extremely conservative, and goes into the conclave with the most votes. However, some experts don't believe he will emerge a winner.

Other possible contenders include several Italian cardinals, a few from South America, and even one from Canada, Cardinal Marc Ouellet.

The only country that likely won't see the election of a pope is the United States, said Vatican Affairs Correspondent Gerry O'Connell.

Unlike previous conclaves, the cardinals will be housed in a new $20-million hotel that John Paul had constructed inside Vatican City so that cardinals could rest in style between voting sessions.

Previously, the cardinals had to live in cubicles, and share bathrooms.

John Paul also changed the voting rules so that after about 30 votes, cardinals could pick a successor based on the majority, rather than the two-thirds rule.

With files from The Associated Press