Jeddah- The United States’ Pentagon on Tuesday warned that whoever fired missiles at a U.S. Navy destroyer and an accompanying ship off the coast of Yemen over the weekend had done so “at their own peril,” language that suggested preparations for possible retaliation.

The Obama administration should “retaliate swiftly and decisively” against the attack, Senator Lindsey Graham said Monday, Kristina Wong reports at the Hill.

“Anybody who takes action, fires against U.S. Navy ships operating in international waters, does so at their own peril,” Pentagon spokesman Captain Jeff Davis told a news briefing, noting the missiles came from territory controlled by Iran-aligned Houthi militants. The vessel was on a routine patrol in international waters, according to officials.

Asked whether the Pentagon was developing targets for retaliatory strikes, Davis said: “I’m not confirming that right now.”

Iran-backed Houthi militias are thought to be to blame after a missile was fired on a US Navy warship in the Red Sea. The USS Mason, a guided missile destroyer, was shot at with rockets but was undamaged.

“USS Mason detected two inbound missiles over a 60-minute period while in the Red Sea off the coast of Yemen. Both missiles impacted the water before reaching the ship,” Pentagon spokesman Captain Jeff Davis said.

“There were no injuries to our sailors and no damage to the ship.”

The Pentagon did not specify how close the missiles came to the U.S.S Mason. However, a U.S. defense official told Reuters the first missile forced the U.S.S Mason to take defensive measures.

Yemen’s Major Gen. Samir Haj told Asharq Al-Awsat that if the international community continues to stand idle against Houthi militants’ usage and ownership of illegal arms, Bab el Mandeb strait is what is at risk.

“We stand against a permanent danger if the international community continues to dismiss wayward gangs and militias possessing weapons,” said Haj.