The Holy See has announced that blood tests showed early signs of kidney failure in Pope Francis, who has been in hospital battling a complex lung infection for over a week.

ROME -- Pope Francis was resting Monday morning after a quiet night, on the 10th day of his hospitalization for a complex lung infection that has provoked the early stages of kidney failure, the Vatican said. The one-line statement didn’t say if Francis, 88, had woken up. “The night passed well, the pope slept and is resting,” it said.

Pope Francis remains in hospital in a critical condition, with the Vatican saying he has presented a "slight improvement".