The head of the World Health Organization (WHO) and other United Nations staff were at Yemen’s main airport when it was hit by Israeli air strikes, killing three people and injuring many others. Tedros Adhanom Ghebreyesus was about to board his plane Thursday when the airport “came under aerial bombardment,” he posted on X. “One of our plane’s crew members was injured. At least two people were reported killed at the airport,” said Ghebreyesus, who was in Yemen to negotiate the release of the U.N. detainees and discuss the country’s humanitarian crisis. “The air traffic control tower, the departure lounge — just a few meters from where we were — and the runway were damaged. We will need to wait for the damage to the airport to be repaired before we can leave,” said Ghebreyesus. Houthi-run news agency Saba said a further three people were killed at another strike in the western Hodeidah province. The U.N. Secretary-General António Guterres condemned the escalation in Yemen. “I regret the recent escalation between Yemen and Israel, and remain deeply concerned about the risk of further escalation in the region,” Guterres said in a post on X. “Today’s airstrikes follow around a year of escalatory actions by the Houthis in the Red Sea and the region that threaten civilians, regional stability and freedom of maritime navigation.” The Israeli military said it targeted “military infrastructure” used by Yemen’s Houthi rebels at the Sana’a airport, as well as ports and power stations, alleging that they are used for smuggling in Iranian weapons. “We are determined to cut off this terrorist arm of Iran’s evil axis. We will persist in this until we complete the task,” said Israeli Prime Minister Benjamin Netanyahu. Israel has held one of the 34 rotating seats on the WHO Executive Board since May this year, after it was nominated by the European region. In response to the attack on Thursday, Javier Padilla, Spain’s State Secretary for Health told POLITICO the country is now considering challenging Israel’s membership. “We are currently seeing what to do. One of the things we are considering is showing the WHO our rejection of Israel’s position in the [executive board]… but we haven’t decided it yet,” Padilla said. Iran-backed Houthi rebels have been attacking Israel since the beginning of the war in Gaza, with the situation having escalated last month as both sides increased the number of attacks. Rory O’Neill contributed reporting to this article.