Israeli forces have raided AlShifa Hospital, where thousands of Palestinians are sheltering, following days of heavy attacks in the area surrounding the complex in Gaza City.

Israel’s military said early on Wednesday morning that it was carrying out an “operation against Hamas in a specified area” at AlShifa. Calling the assault a “targeted operation” on Gaza’s largest medical facility, it said the raid was based on Israeli and United States intelligence.

Israel accuses Hamas, the group that governs Gaza, of using the hospital as a base. Hamas rejects the claim. Israel has not produced evidence to back up its assertion.

Dozens of Israeli soldiers entered the facility while tanks were stationed in the courtyard of the medical complex.

According to health officials, there are about 650 patients, including 22 in intensive care and 36 premature babies, at AlShifa Hospital, in addition to some 400 medical staff and more than 2,000 displaced people. Israeli forces searched the basement of Al Shifa and entered the surgical and emergency buildings within the complex. More than 1,000 medical staff are also trapped on site, but they are unable to treat patients due to a shortage of medicine and fuel.

According to sources inside AlShifa, Israeli soldiers are using loudspeakers and ordering young men to surrender themselves. About 30 people were reportedly taken out into the courtyard, stripped of their clothes, blindfolded and interrogated by Israeli soldiers. Israeli forces have also blown up a warehouse of medicine and medical devices. Heavy gunfire and explosions could be heard in the compound.

Thousands of civilians displaced by Israel’s five-week bombardment of Gaza, which has killed more than 11,200 Palestinians, are also inside Al Shifa Hospital.

The area around al-Shifa has been battered by multiple Israeli attacks for weeks. The Israeli government has issued warnings to evacuate the facility. However, Palestinian medical officials have rejected the order, saying they cannot leave their patients behind.