Yemen’s Houthi rebels on Saturday vowed to retaliate against Saudi Arabia, accusing the kingdom of targeting civilian infrastructure in Yemen, as the conflict in the Middle East expanded into a new front.

The warning came a day after the Saudi-led coalition said it had launched strikes on Houthi military targets in Yemen’s western Hodeida province in response to attacks on commercial shipping in the Red Sea.

In a statement posted on Telegram, the Houthis’ Ansarollah media condemned what it described as Saudi attacks on civilian facilities in Hodeida and Kamaran Island, calling them a “dangerous escalation.”

“We affirm that these recent crimes will not go unanswered,” the group said.

A Yemeni security source told Agence France-Presse that a naval base in the port city of Hodeida and a military camp on Kamaran Island were among the sites targeted in the Saudi operation.

The Saudi-led coalition said it struck Houthi military positions that were being used to threaten commercial vessels in the Red Sea, describing the operation as a proportionate response to attacks on maritime shipping.

Coalition spokesperson Turki Al Maliki said Houthi forces had targeted commercial ships in the Red Sea, prompting what he called a “decisive and strong response” against military sites used to launch such attacks.

He added that the military operation had concluded.

The latest escalation follows the Houthis’ announcement of a maritime blockade targeting Saudi Arabia and claims that they attacked two Saudi-linked vessels earlier this week.

Riyadh has confirmed that one commercial ship was attacked in the Red Sea.

The confrontation opens another front in the widening regional conflict, which has already seen Iran impose a parallel blockade in the Strait of Hormuz, increasing pressure on one of the world’s most critical energy shipping corridors.