UN Special Envoy for Yemen Hans Grundberg condemned on Saturday the Houthis’ attack against al-Dhabba oil terminal in Yemen’s Hadramawt governorate, warning it was a “deeply worrying military escalation.”

“At this critical juncture, I call on the parties to show utmost restraint and double their efforts to renew and expand the truce and lay the groundwork for a permanent ceasefire, and activating a political process to end the conflict,” Grundberg said in a statement.

On Friday, the internationally-recognized government of Yemen said that its forces intercepted armed drones launched against al-Dhabba oil terminal, located in the town of al-Shihr in Hadramawt, as an oil tanker was preparing to dock.

The incident is the first major escalation since the Houthis and the Yemeni government failed to renew a UN-brokered truce.

The US and the EU also denounced the attack warning that such operations hinder the flow of goods and jeopardize maritime navigation.

“We call on the Houthis to immediately halt such attacks, which are an affront to navigational rights and freedoms and jeopardize international commerce,” the US Embassy in Yemen said in a statement.

It also said that such attacks threaten Yemen’s peace and security and hamper the flow of essential goods, warning that they will only result in “further economic instability across the country.”

“We remind the Houthis that the world is watching their actions, and that the only path forward to ending eight years of destructive war is to de-escalate and redouble efforts to reach a durable ceasefire and end Yemen’s conflict through a negotiated political statement.”

The EU Delegation to Yemen echoed the US embassy’s warnings saying that the “Houthi attacks on international shipping are an affront to core principles of the Law of the Sea, jeopardizing freedom of navigation through the region’s waterways and blocking access to Yemeni ports.”

It also reaffirmed its support of efforts led by Grundberg to renew the truce which expired earlier in October.

“The path forward is to reduce tensions, de-escalate and redouble efforts to end Yemen’s conflict through a negotiation settlement,” it added in a statement.

Meanwhile, Yemen’s government sent a letter to the UN Security Council regarding what it described as the Iran-backed Houthi militia’s “threat to disrupt international maritime navigation and target ships and oil infrastructures.”

It noted that in addition to the attack on al-Dhabba on October 21, the Houthis launched “terrorist” attacks targeting the Rudhoum oil terminal on October 18 and October 19.

The government also slammed the Houthis, accusing them of “crossing all the red lines,” at a time when it practices restraint and supports efforts to renew the truce.

“[We] call on the [UN Security] Council to strongly condemn this terrorist attack and the Iranian regime behind it,” it said, urging the Council to adopt tangible measures to end “this terrorist behavior” which disrupts the peace process in Yemen and jeopardizes the stability of global energy markets.