SANA, Yemen — The Houthi movement and its allies formed a new government in Yemen on Monday, a surprise that angered their Saudi-backed rivals and complicated United Nations efforts to end a conflict that has ravaged the Arab world’s poorest country for much of the past two years.

The announcement of the new government, reported by the Houthi-run state television and Saba news agency, said it was formed from “all walks of the political spectrum who are anti-aggression.”

The reference was a swipe at the coalition led by Saudi Arabia that supports Yemen’s president, Abdu Rabbu Mansour Hadi, who was driven into Saudi exile in 2014 after the Houthis routed him from Sana, the capital. The Houthis control a large portion of Yemen including Sana.

The Saudi coalition has been bombarding Houthi positions in Yemen since March 2015 with thousands of airstrikes that have raised worldwide criticism over civilian deaths and destruction.