VATICAN CITY — The heavy wooden door to the Sistine Chapel has been closed and locked, signaling the start of the conclave to elect a new pope to succeed Benedict XVI following his stunning resignation.

Monsignor Guido Marini, master of liturgical ceremonies, closed the double doors after shouting “Extra omnes,” Latin for “all out,” telling everyone but those taking part in the conclave to leave the frescoed hall. He then locked it.

Benedict’s resignation has thrown the church into turmoil and exposed deep divisions among cardinals grappling with whether to pick a manager who can clean up the Vatican bureaucracy or a pastor who can inspire Catholics at a time of crisis.