"We support the calls of the secretary-general for an immediate de-escalation of tensions and his demand that both sides should do everything to avoid further escalation and must respect their obligations under international humanitarian law to ensure the protection of civilians at all times," said the U.N. Relief and Works Agency for Palestine Refugees in the Near East.
UNRWA staff member Marwan Abu El Qumsan was killed Thursday in an airstrike in the northern Gaza city of Jabalia, the agency said.
Adnan Abu Hasna, an UNWRA spokesperson in Gaza, said schools operated by the agency in Gaza had been temporarily closed because of the violence but international staff members were still working, assisting with emergency operations.
The U.N. Office for the Coordination of Humanitarian Affairs said widespread panic in Gaza had caused a "precarious" humanitarian situation. Residents were stockpiling food and fuel while drugs and medical supplies were at low levels.
Entry points for humanitarian goods had been closed, OCHA added.
Israeli schools within 25 miles of the Gaza border were closed and movement limited, OCHA said.