Three nurses at Al-Shifa have reportedly been killed as "bombardments and armed clashes" around the hospital have intensified, the UN says. In an update on Sunday, the UN says critical infrastructure at the hospital has also been damaged, including an oxygen-generation facility, water tanks and a well, the cardiovascular facility and the maternity ward. Gaza's Hamas-run health ministry has said there are at least 2,300 people still inside the hospital. The numbers have been provided to the World Health Organization, who shared them in a post on X, formerly known as Twitter. The update says there are between 600 and 650 inpatients in the hospital, as well as 200 to 500 health workers and around 1,500 displaced people who have sought shelter. It adds that the lack of power, water, and food at the site is "putting lives at immediate risk". The WHO repeats its call for an "immediate ceasefire" and the "active protection of civilians and health care". Israel has previously accused Hamas of operating an underground command center beneath the site of Gaza's largest hospital, which Hamas denies. Asked whether Hamas was operating inside Al-Shifa, the hospital's head of surgery Dr Marwan Abu Saada said the allegations were a "big lie". "We are civilians. I am a doctor-surgeon. We have medical staff, we have patients, and displaced people. Nothing else." In recent days the area around Al-Shifa in northern Gaza has experienced heavy fighting, with Israel being accused of attacking the hospital directly. The Israeli military says it is operating in the area of the hospital, but denies attacking the facility. Israeli President Isaac Herzog also denied that Israel is striking Gaza's largest hospital. Reports from staff at Al-Shifa suggest the facility, sheltering thousands of Palestinians, has run out of electricity. But, speaking to the BBC's Laura Kuenssberg, Herzog said "everything is operating" at the hospital. Earlier, WHO said it had lost communication with its contacts at Al-Shifa, with staff and patients trapped by fighting outside. WHO chief Dr Tedros Ghebreyesus later said that contact has been restored but warned of "dire" conditions inside. He repeated calls for a ceasefire and said the hospital has been without electricity and water for three days. Doctors and the Hamas-run health ministry in Gaza have said a lack of fuel there means patients cannot be operated on and incubators for premature babies cannot run. But the president disputed this. Surgeon Marwan Abu Saada told the BBC on Saturday that the hospital had run out of water, food and electricity. He said the sounds of shooting and bombardments echoed through the hospital "every second". Israeli military spokesman Rear Admiral Daniel Hagari said Israel would help evacuate babies from Al-Shifa following a request from the hospital administration. A doctors group said on Saturday that two premature babies had already died. More than 11,000 people have been killed in Gaza since the start of the war, according to the Hamas-run health ministry. More than 1.5m people are also displaced, according to the United Nations' agency for Palestinian refugees (UNRWA). The United Nations will fly its flag at half mast Monday, as a "mark of respect" for its staff killed in Gaza. The UNRWA said on Friday that more than 100 of its employees have died in Gaza since the Israeli bombardment began. Israel launched an offensive in the Gaza Strip following Hamas's deadly 7 October attack, which killed 1,200 people and saw more than 200 others taken hostage from southern Israel. Fighting has been fierce in the northern part of the 41km (25 miles) long and 10km wide enclave, but blasts have also hit the southern cities of Rafah and Khan Younis. — BBC