The Israeli military says its forces have entered Gaza’s Shifa Hospital, the site of a lengthy standoff.

The army has surrounded the facility as part of its ground offensive against Hamas. Israeli authorities claim the militant group conceals military operations in the facility. But with hundreds of patients and medical personnel inside, it has refrained from entering.

Early Wednesday, the army said its forces were carrying out “a precise and targeted operation against Hamas in a specified area” in the hospital. It gave no further details but said it was taking steps to avoid harm to civilians.

“In recent weeks, the IDF has publicly warned time and again that Hamas’ continued military use of the Shifa Hospital jeopardizes its protected status under international law,” it said.

“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.”

Hamas has denied the Israeli accusations that it uses the hospital for cover.