Black smoke has billowed from the chimney above the Sistine Chapel, signalling that the 133 cardinals have failed to agree on a new pope during the first vote of the conclave.

The historic and secretive process to elect a successor to Pope Francis, who passed away earlier this year, will continue tomorrow. From Thursday, cardinals will hold up to four votes a day until a new leader of the Catholic Church is chosen.

Tens of thousands have gathered in St Peter’s Square to witness the moment. According to local police, an estimated 45,000 people are packed into the square, watching and waiting for the signal that a decision has been made.

Earlier tonight, the great doors of the Sistine Chapel were sealed after the traditional cry of “extra omnes” (“everyone out”) was made, leaving only the cardinals behind to begin the solemn ritual.

Among the key figures in the conclave is Cardinal Pietro Parolin, the former Secretary of State under Pope Francis, widely considered a leading contender to become the next pontiff.

The world now waits as the conclave resumes.