The Israel Defense Forces says it is carrying out a “precise and targeted operation against Hamas in a specified area” of Al-Shifa hospital in Gaza.

The ground operation, based on intelligence and “operation necessity,” came after the Israeli military had repeatedly warned Hamas against using the hospital as a base for its operations, the IDF said in a statement issued Wednesday morning local time.

“Yesterday, the IDF conveyed to the relevant authorities in Gaza once again that all military activities within the hospital must cease within 12 hours. Unfortunately, it did not,” the Israeli military said, adding that Hamas’s alleged use of the hospital violates international law.

The announcement came one day after President Biden said that hospitals in the Gaza Strip “must be protected.” 

“My hope and expectation is that there will be less intrusive action relative to hospitals,” Mr. Biden said in response to questions from journalists.

The IDF said its forces involved in the operation include medical teams and Arabic speakers “who have undergone specified training to prepare for this complex and sensitive environment, with the intent that no harm is caused to the civilians being used by Hamas as human shields.”

Al-Shifa is in the heart of Gaza City and at the center of a tense standoff. The World Health Organization has called the situation for patients at the Palestinian territory’s largest hospital “dire and perilous.” 

Israel accuses Hamas of having an underground headquarters under the sprawling facility, which both Hamas and doctors at Al-Shifa deny. Both Israeli and U.S. officials have stressed that Hamas has a long history of positioning weapons and fighters in civilian homes, schools and hospitals.

On Tuesday, U.S. National Security Council coordinator for strategic communications John Kirby said, “We have information that Hamas and Palestinian Islamic Jihad use some hospitals in the Gaza Strip, including Al Shifa Hospital, and tunnels underneath them to conceal and support their military operations and hold hostages.”

Kirby said that Hamas and Palestinian Islamic Jihad operate a “command and control node” from Al-Shifa, adding, “Now to be clear, we do not support striking a hospital from the air and we don’t want to see a firefight in a hospital where innocent people, helpless people, sick people trying to get medical care they deserve are caught in the crossfire. Hospitals and patients must be protected.” 

Hamas attacked Israel on Saturday, Oct. 7, prompting Israeli Prime Minister Benjamin Netanyahu to declare, “We are at war.” Israel says at least 1,200 people there, most of them civilians, were killed in the coordinated, multi-fronted terror attack launched from the Gaza Strip, the Palestinian territory Hamas has controlled for years. 

Netanyahu has said a cease-fire will be possible only if the approximately 240 hostages held in Gaza are released. But Israel’s punishing response has divided the international community. 

More than 11,070 Palestinians, two-thirds of them women and minors, have been killed since the war began, according to the Health Ministry in Hamas-controlled Gaza, which does not differentiate between civilian and militant deaths. About 2,700 people have been reported missing and are thought to be possibly trapped or dead under the rubble. 

The U.N. estimates that some 1.5 million people — more than two-thirds of Gaza’s population — have fled the intense fighting in the north of Gaza to head south. Meanwhile, about 250,000 Israelis have been forced to evacuate from communities near Gaza and along the northern border with Lebanon, where Israeli forces and Hezbollah militants have traded fire repeatedly.

—Camilla Schick, Margaret Brennan and Haley Ott contributed reporting.