Recent developments in the Red Sea and surrounding waterways suggest that the threat to international shipping from Yemen’s Houthis is growing, U.N. Special Envoy to Yemen Hans Grundberg told the U.N. Security Council on Tuesday.

In a briefing on the situation in Yemen, Grundberg warned of a real danger of a devastating regional escalation following new Houthi attacks on commercial shipping and the first Israeli air strikes on Yemen in retaliation for Houthi drone and missile attacks on Israel.

“I remain deeply concerned about the continued targeting of international navigation in the Red Sea and its surrounding waterways,” Grundberg said. “Recent developments suggest that the threat against international shipping is increasing in scope and precision.”

The Houthi attacks on Israel and July 20 Israeli retaliatory strikes on Yemen’s port of Hodeidah and its oil and power facilities represent “a new and dangerous level” of violence, he said.

Commercial ships have been sunk and damaged, disrupting trade, civilians have died, the Houthis still detain the crew of the Galaxy Leader, a cargo ship they hijacked in November, and the United States and Britain continue airstrikes on military targets in Houthi-controlled areas of Yemen, he said.

“It is alarming that there are no signs of de-escalation, let alone a solution,” Grundberg continued.

The Houthis have launched missiles and drones at Israel and disrupted global trade through the Red Sea in response to Israel’s assault on Gaza.

Israel says the Iran-backed Houthis have launched 200 attacks against it since the war began, many of them intercepted and most of them not deadly.

But a rare Houthi drone strike last Friday hit Tel Aviv, killing one person and prompting Israel to announce its first strikes against the group on Saturday. The airstrikes hit near the Hodeidah and killed six people, local medics said.

Israel said it shot down a missile launched by the Houthis on Sunday.

Source: Reuters, reported by Jonathan Landay and edited by Mark Porter, Alexandra Hudson