Thousands of people gathered in St. Peter’s Square Monday evening to pray for an ailing Pope Francis, expressing sorrow for his suffering, hope for his recovery and gratitude for his efforts to steer the Catholic Church in new directions.

The Vatican said that the pontiff had pneumonia in both lungs and that he “continued to present a complex picture.”

Pope Francis has the onset of double pneumonia, the Vatican said on Tuesday, complicating treatment for the 88-year pontiff and indicating a further deterioration in his fragile health.