The World Health Organization (WHO) on Friday voiced concern over the fate of the head of Gaza City's al-Shifa hospital, Mohammad Abu Salmiya, whom Israeli occupation forces arrested.

In a statement, the WHO said that the head of the biggest hospital in the besieged Gaza Strip had been arrested on Wednesday along with five other health workers, while they were taking part in a UN mission to evacuate patients.

"Three medical personnel from the Palestine Red Crescent Society and three from the Ministry of Health were detained," the WHO said.

Since then, two of the six have reportedly been released, but "we do not have information about the well-being of the four remaining health staff, including the director of Al-Shifa hospital," the statement added.

The UN agency called for "their legal and human rights to be fully observed during their detention."

Abu Salmiya has been frequently quoted by international media about the conditions inside al-Shifa, which had been targeted and raided by Israeli occupation forces since the start of their ground invasion of the Gaza Strip.

On Thursday the Israeli occupation military announced it had arrested the hospital chief, along with a department head.

According to the WHO statement, the organization has carried out three missions to al-Shifa in the space of a week, on one occasion managing to evacuate 31 babies from the hospital.

During the third mission, on Wednesday, which was carried out in cooperation with the Palestinian Red Crescent, 151 people were evacuated, including patients, their relatives and healthcare workers, according to the WHO.

It is noteworthy that the WHO had described the al-Shifa Hospital as a "death zone". The assessment followed a visit by WHO and other UN officials to the hospital.

Earlier on Friday, the Health Ministry in Gaza confirmed that Israeli occupation forces withdrew from al-Shifa Hospital on the first day of the temporary truce between the Palestinian Resistance and the Israeli occupation.

But the WHO was "extremely concerned" about the safety of the estimated 100 patients and health workers remaining at al-Shifa, spokesman Christian Lindmeier said.

Health Ministry spokesman Ashraf al-Qudra said the Israeli occupation military had withdrawn but the people remaining at al-Shifa were in a battered complex whose "main generator is destroyed along with numerous buildings."

"We're working on further evacuations from hospitals as soon as possible," said Lindmeier, highlighting that the latest evacuation convoy had left al-Shifa with "73 severely ill or injured patients" including some in need of critical care.

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