An attack in Rafah killed a United Nations staff member working there, UN Secretary-General António Guterres announced on Monday. The Deputy Spokesman for the Secretary-General, Farhan Haq, said that one staff member from the Department of Safety and Security (DSS) had been killed and another injured “when their UN vehicle was struck as they traveled to the European Hospital in Rafah.” Guterres called for a full investigation into the incident.

The individual killed was an international staff member, which the UN says is the first death of its kind since the conflict began. The Secretary-General made a call for the protection of humanitarian workers and stated that he condemned “all attacks on UN personnel”  and reiterated his “urgent appeal for an immediate humanitarian ceasefire & the release of all hostages.”

The attack has come just days after Israel launched its latest offensive in Rafah, a move opposed by UN High Commissioner for Human Rights Volker Türk. Since the first evacuation order was given last week, nearly 360,000 people have fled the city according to the UN Agency for Palestinian Refugees (UNRWA). Guterres has repeatedly called for Israeli and Hamas leaders to reach a ceasefire agreement.

Just last month, an attack on an aid convoy, killed seven aid workers including three Britons, a Palestinian, a US-Canadian dual citizen, a Pole and an Australian. According to the US-Funded Aid Worker Security Database, around 200 aid workers have been killed in Gaza since October.

The European Commissioner for Crisis Management, Janez Lenarčič, who heads up EU humanitarian aid, said that he condemned “today’s attack on a humanitarian convoy while on a mission of saving lives in #Gaza. My condolences to the family of the killed worker.”