VATICAN CITY: Pope Francis, in critical condition battling double pneumonia, had a “tranquil” night and rested following a respiratory crisis and blood transfusions, the Vatican said on Sunday.

The pope was admitted to Rome’s Gemelli hospital on February 14 after experiencing difficulty breathing for several days and subsequently had pneumonia diagnosed in both lungs.

The Vatican described his condition as critical for the first time on Saturday, reporting that the 88-year-old Francis had needed supplemental oxygen and blood transfusions that day after a “prolonged asthma-like respiratory crisis”.

“The night was tranquil, the pope rested,” the Vatican said in a one-sentence update on Sunday morning without providing further information. A further update on the pope’s condition is expected later in the day.

Archbishop Rino Fisichella, a senior Vatican official, told participants at a Mass in St Peter’s Basilica on Sunday morning they should make their prayers for Francis “stronger and more intense”.

The Diocese of Rome, which the pope leads, announced a special Mass for Sunday evening to pray for Francis, so that he will have “the strength necessary to get through this moment of trial”.

Double pneumonia is a serious infection that can inflame and scar both lungs, making it difficult to breathe. The Vatican has described the pope’s infection as “complex”, saying it is being caused by two or more microorganisms.

Francis, who has been pope since 2013, has suffered bouts of ill health in the past two years. He is particularly prone to lung infections because he developed pleurisy as a young adult and had part of one lung removed.