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.

Francis is being treated for pneumonia, a complex infection and kidney problems that have left him in critical condition. He did some light work on Monday.

Pope Francis was in critical condition Saturday after he suffered a long asthmatic respiratory crisis that required high flows of oxygen, the Vatican said.