The Vatican on Monday announced the start of nighttime prayers for the health of Pope Francis in St. Peter's Square, and invited Romans and others to join in, as the 88-year-old pontiff battled a complex lung infection and complications.

Pope Francis was in critical condition Saturday after he suffered a long asthmatic respiratory crisis that required high flows of oxygen, the Vatican said.

Francis remains in critical condition but has not suffered any additional crises, the Vatican said Sunday evening, after reporting Saturday the pope suffered a “long asthmatic respiratory crisis” days after he was hospitalized for pneumonia.