Pope Francis was conscious but still receiving high flows of supplemental oxygen Sunday following a respiratory crisis and blood transfusions, as he remains in critical condition with a complex lung infection,

Pope Francis, who is battling double pneumonia in hospital, had a "tranquil" night and rested, the Vatican said on Sunday. It comes after news that the Pope's health had deteriorated over the past 24 hours.

Francis, 88, is in critical condition at a Rome hospital with a complex lung infection. The Vatican said he was "alert and spent the day in an armchair" on Saturday.