The United States Friday condemned the latest Houthi attack, which targeted an oil refinery in Saudi Arabia’s Riyadh and caused a fire.

The Iran-backed Houthis have escalated their attacks on Saudi Arabia since US President Joe Biden took office and revoked the terror designation against the Yemeni group. Biden also removed three senior Houthi officials from the Specially Designated Global Terrorist (SDGT) list.

“We condemn the attempts by the Houthis to disrupt the world’s energy supply by targeting Saudi infrastructure,” a State Department official told reporters during a phone briefing.

Such attacks demonstrate a blatant disregard for civilians that work and live near the oil refineries, Deputy Spokesperson Jalina Porter said.

The increase of attacks has become a growing concern for the US, Porter added.