The UN Secretary-General has expressed grave concern over US airstrikes in and around Yemens port of Ras Isa this week, which reportedly resulted in scores of civilian casualties.

After several years of fragile truce, there is a palpable fear of a return to all-out war in Yemen, said Special Envoy of the Secretary-General for Yemen Hans Grundberg on Thursday, briefing the Security Council.

At least five humanitarian workers were said to be among those injured, and significant damage was reported to port infrastructure. There are also fears of oil leaks into the Red Sea, raising environmental concerns.

In astatementissued on Saturday by his spokesperson, Antnio Guterres emphasised that international law, including international humanitarian law, must be respected at all times.

He urged all parties to respect and protect civilians and civilian infrastructure.

The Secretary General also voiced deep concern over ongoing missile and drone attacks by Houthi forces against Israel and vessels in the Red Sea, calling on the group to cease such attacks immediately.

TheSecurity Councilresolution 2768 (2025)related to Houthi attacks against merchant and commercial vessels must be fully respected, he stressed.

Mr. Guterres also warned of the growing risk of a broader regional escalation and urged all parties to exercise utmost restraint.

He also reiterated his demand for the immediate and unconditional release of all UN and other personnel arbitrarily detained by the Houthis.