Plumes of black smoke have emerged from the chimney on top of the Sistine Chapel, signalling that the 133 cardinals sealed off inside have failed to elect a new pope on the first day of conclave.

After the formal procession to the Sistine Chapel and each of the cardinals swearing the oath to secrecy, the first voting round only got under way at about 5.45pm local time. Then all eyes were on the famous chimney, which was diligently guarded by a seagull for some of the time the cardinals were voting.

After a tense wait, black smoke finally appeared at 9:05pm – to loud applause from the crowd of more than 45,000 below.

The conclave will continue on Thursday, and end only when a successor to Pope Francis, who died last month aged 88, is found.

St Peter’s Square was packed even though the pope was not expected to be elected on the first day.

Cinzia Caporali and her husband, from Tuscany, had come to Rome to visit Pope Francis’s tomb at Santa Maria Maggiore basilica in the Esquilino neighbourhood.

Caporali recalled being in the Italian capital the moment Francis’s predecessor Benedict XVI was elected in April 2005. The conclave that chose Joseph Ratzinger was over in less than 36 hours, one of the fastest papal elections in a century.

“I was in a cafe not far away and people were shouting: ‘Fatto, fatto, fatto!’ [It’s done]. Then I went outside and saw the white smoke,” said Caporali.

Now she was eagerly waiting to hear who the new pope would be. “I hope it will be a continuation of Francis,” she said. “He was for the marginalised people, and we need to make sure this continues. We don’t want to see the flashy richness of the church, this is no longer in fashion.”

In his homily during the cardinals’ pre-conclave mass in St Peter’s Basilica on Wednesday morning, Giovanni Battista Re, the Italian cardinal who also led the funeral mass of Pope Francis, appeared to call for the same.

Re implored the voters to cast aside all “personal considerations”, adding that choosing a new pope was “an act of maximum responsibility”.

“We are here to invoke the help of the holy spirit, to implore his light and strength so that the pope elected may be he whom the church and humanity need at this difficult and complex turning point in history,” he said.

He also urged them to be guided by love, because “love is the only force capable of changing the world”.

Finding a suitable successor to Francis is a tough task, partly because he left behind a diverse but divided college of cardinals. Many cardinals had not met each other before travelling to Rome for his funeral. Some are in harmony with the progressive church Francis promoted during his 12-year papacy, while others want to overthrow his changes and turn back the clock.

Still, the feeling before the conclave was that no cardinal wanted the election to last for more than two or three days, in part because they do not want to give the impression that the Catholic church is divided.

During twice-daily pre-conclave meetings in the run-up to the vote, the cardinals shared their visions on the future of the Catholic church and discussed issues including evangelisation, the Vatican’s finances, clerical sexual abuse, war and service to the poor and migrants.

But one topic missing from the agenda was the role of women in the church, something that Francis was keen to promote, even if he repeatedly said women could never become priests.

Catholic women’s groups, which for years have fought for women’s ordination, have converged in Rome in recent days.

Bursts of pink smoke filled the air on Gianicolo hill, which overlooks St Peter’s, before the conclave began. The smoke was part of a peaceful protest organised by advocates from the UK-based group Catholic Women’s Ordination (CWO).

“The cardinal-electors – 133 men – will use smoke signals to communicate to the world they have elected a new pope,” said Miriam Duignan, who led the CWO advocates. “As they refuse to listen to women and have rendered one half of the population of the global church silent and subservient, we communicated with them, also via smoke signals, in the hope they might open their eyes to the injustice they are upholding.”