UPDATE: Black smoke again pours from Sistine Chapel chimney, indicating no pope elected after second or third ballots.

VATICAN CITY (AP) — Cardinals return to the Sistine Chapel on Thursday to resume voting for a new pope after the first conclave ballot failed to find a winner, sending billowing black smoke through the chapel chimney.

Some of the 133 voting cardinals had said they expected a short conclave to replace Pope Francis. But it will likely take a few rounds of voting for one man to secure the two-thirds majority, or 89 ballots, necessary to become the 267th pope.

For much of the past century, the conclave has needed between three and 14 ballots to find a pope. John Paul I — the pope who reigned for 33 days in 1978 — was elected on the fourth ballot. His successor, John Paul II, needed eight. Francis was elected on the fifth in 2013.

The cardinals opened the secretive, centuries-old ritual Wednesday afternoon, participating in a rite more theatrical than even Hollywood could create.

Cardinal Pietro Parolin, the 70-year-old secretary of state under Francis and a leading contender to succeed him as pope, assumed leadership of the proceedings as the senior cardinal under age 80 eligible to participate.

Parolin stood before Michelangelo’s vision of heaven and hell, “The Last Judgment,” and led the other cardinals in a lengthy oath. Each one followed, placing his hand on the Gospel and promising in Latin to maintain utmost secrecy. The ritual a wash of red-robed cardinals, Latin chants, incense and solemnity that underscored the magnitude of the moment.

Outside in St. Peter’s Square, the scene was festive as thousands of people flocked to the piazza to watch the proceedings on giant video screens, applauding when the Sistine Chapel’s doors slammed shut and the voting began.

They waited for hours, watching screens that showed just a skinny chimney and occasional seagull. After the vote dragged on to dinnertime, some left in frustration, but those who stayed cheered when the smoke finally billowed out.

“My hope is that cardinals will choose a man who can be a peacemaker and could reunify the church,” said Gabriel Capry, a 27-year-old from London.

The cardinals were sequestered from the outside world Wednesday, their cellphones surrendered and airwaves around the Vatican jammed to prevent all communications until they find a new pope.

Francis named 108 of the 133 “princes of the church,” choosing many pastors in his image from far-flung countries like Mongolia, Sweden and Tonga that had never had a cardinal before.

His decision to surpass the usual limit of 120 cardinal electors has both lengthened the amount of time it takes for each vote to be processed and injected more uncertainty into a process that is always full of mystery and suspense.