Pope Francis remained in critical condition Monday but showed slight improvement in laboratory tests and resumed some work, the Vatican said, including calling a parish in Gaza City that he has kept in touch with since the war there began.

Time-honored rituals, drafted and refined over centuries, allow for ritual mourning and provide order at a dramatic moment of transition.

Pope Francis, in critical condition battling double pneumonia, had a "good" night in hospital, slept and is resting, the Vatican said on Monday.