VATICAN CITY: Cardinals resume their vote of papal conclave Wednesday morning, after black smoke pouring from the Sistine Chapel chimney Tuesday, signaled they had failed on their first vote to choose a new leader for the world’s 1.2 billion Catholics and their troubled church.

The cardinals returned to the Vatican hotel for the night.

Surrounded by Michelangelo’s imposing frescos imagining the beginning and the end of the world, cardinals locked themselves into the chapel Tuesday afternoon, following a final appeal for unity to heal the divisions that have been exposed by Pope Benedict XVI’s shocking resignation and revelations of corruption and mismanagement in the Vatican bureaucracy.

Led by prelates holding a crucifix and candles, the 115 scarlet-robed prelates chanted the Litany of Saints, the hypnotic Gregorian chant imploring the intercession of the saints to guide their voting, before the master of liturgical ceremonies intoned “Extra omnes” or “all out” and closed the heavy wooden doors.

Outside, thousands of people braved cold night rain and packed St. Peter’s Square, eyes fixed on the narrow chimney poking out of the Sistine Chapel roof. They were rewarded some three hours after the conclave began when thick black smoke billowed out of the chimney, signaling that no pope had been elected.

Benedict XVI’s surprise resignation has thrown the church into turmoil and exposed deep divisions among cardinals grappling with whether they need a manager to clean up the Vatican’s dysfunctional bureaucracy or a pastor who can inspire Catholics at a time of waning faith and growing secularism.

The leading contenders for pope have fallen into one of the two camps, with Cardinal Angelo Scola, seen as favored by those hoping to shake up the powerful Vatican bureaucracy, and Brazilian Cardinal Odilo Scherer, favored by Vatican-based insiders who have defended the status quo. Other names included Canadian Cardinal Marc Ouellet, who heads the Vatican’s powerful office for bishops, and U.S. Cardinal Timothy Dolan, the exuberant archbishop of New York.

In a final appeal before the conclave began, the dean of the College of Cardinals, retired Cardinal Angelo Sodano, urged unity within the church, asking the cardinal electors to put their differences aside for the good of the church and the future pope.

“Each of us is therefore called to cooperate with the Successor of Peter, the visible foundation of such an ecclesial unity,” Sodano said. He said the job of pope is to be merciful, charitable and “tirelessly promote justice and peace.”

He was interrupted by applause from the pews – not so much from the cardinals – when he referred to the “beloved and venerated” Benedict XVI and his “brilliant” pontificate.

Sitting in the front row was Benedict’s longtime aide, Archbishop Georg Gaenswein, who reported that Benedict was watching the proceedings from the papal residence in Castel Gandolfo, according to a Vatican spokesman the Rev. Thomas Rosica.

For over a week, the cardinals have met behind closed doors to try to figure out who among them has the stuff to be pope and what his priorities should be. But they ended the debate Monday with questions still unanswered, and many cardinals predicting a drawn-out election that will further expose the church’s divisions. The conclave proceeds in silence, with no formal debate, behind closed doors. In other developments Tuesday, a group of women who say they are priests launched pink smoke from a balcony overlooking the square to demand female ordination. Two topless activists from Femen were dragged away from the edge of St. Peter’s Square by police.

While few people expect a pontiff to be elected on the first ballot, the Vatican was ready: In the Room of Tears off the Sistine Chapel, three sizes of white cassocks hung from a clothes rack. Underneath, seven white shoe boxes were piled, presumably containing the various sizes of the red leather shoes that popes wear. The room gets its name from the weight of the job thrust upon the new pontiff.

But with so much uncertainty and upheaval going into the conclave, even the American cardinals couldn’t agree on whether to expect a short or long conclave.

Cardinal Dolan this week publicly expressed optimism that the election would be wrapped up quickly. And on the eve of the conclave, he wrote a letter to New York priests, saying: “My guess is that we’d have a new Successor of St. Peter by Thursday evening,” according to Dolan’s spokesman, Joseph Zwilling.

That bullish stance stood in stark contrast with the view of Chicago Cardinal Francis George: His spokeswoman, Colleen Dolan, told the Associated Press that the cardinal suggested it could be a long affair. George raised the possibility that the cardinals may still be meeting by Saturday, when conclave rules require the cardinals to take a break and spend some time in prayer before resuming voting.