Israeli forces left Al Shifa Hospital in Gaza City on Monday after the two-week operation by special forces, who detained hundreds of suspected Palestinian and left a wasteland of destroyed buildings. Israel said it killed hundreds of Hamas fighters who had based themselves there; Hamas and medical staff deny fighters were present.
"We've had contact with the staff. The directors told us that Al Shifa Hospital is gone. It's no longer able to function in any shape or form as a hospital," said WHO spokesperson Margaret Harris.
"Destroying Al Shifa means ripping the heart out of the health system."
The WHO is hoping to send a mission on Tuesday to the site to see what it can do to save the lives of the remaining patients. Harris said she did not have information about whether Israel had granted permission to carry out such a mission.
"We've been trying to go for days and days and days," she said. "Most of our missions were rejected."
Al Shifa, the Gaza Strip's biggest hospital before the war, was one of the few healthcare facilities that had been partially operational in the north of enclave before the raid.
Palestinian officials called the assault on a hospital treating severely wounded patients a war crime. Israel says Hamas deliberately operates among vulnerable civilians.