Israel on Friday defended its raid on a north Gaza hospital last week while the U.N. human rights chief called the justification unsubstantiated and the World Health Organization urged Israel to release the hospital's director from detention.

Israel faced mounting pressure Saturday over its detention of Gaza hospital chief Dr. Hussam Abu Safiya, during a raid on Kamal Adwan hospital.

Amid international scrutiny, Israel defends its raid on Kamal Adwan Hospital in Gaza, citing security threats from militant activities. The UN and WHO challenge Israel's rationale, demanding investigations into attacks on medical facilities.

A recent report by the UN Human Rights Office indicates that Israeli military operations in Gaza have severely compromised the region's health care infrastructure. The report documents numerous attacks on medical facilities,

UN human rights chief Volker Turk has said Israeli attacks on hospitals in Gaza may constitute a war crime. The Israeli military has repeatedly accused Hamas of using hospitals as command centers, although Turk said this week that Israel did not "substantiate many of these claims,