Military action is not a solution to the crisis in Yemen, European Union foreign policy chief Federica Mogherini said Thursday, urging regional powers to act responsibly.

Warplanes from Saudi Arabia and Arab allies struck Shiite Muslim rebels fighting to oust Yemen’s president Thursday.

“I’m convinced that military action is not a solution,” Mogherini said in a statement. “At this critical juncture all regional actors should act responsibly and constructively, to create as a matter of urgency the conditions for a return to negotiations.”