The men, on a motorbike, attacked low-ranking officer Ibrahim Hassan al-Sharfi near his Sanaa home late Thursday before they fled.

The Houthis’ Al-Masirah television confirmed the attack.

The militia group has been under fire from a Saudi-led air campaign that began in March, as they are locked in battle with pro-government fighters, Sunni tribesmen and southern separatists.

Al-Qaeda and the Islamic State of Iraq and Syria (ISIS) group have also carried out several deadly attacks against the rebels.

Tribal sources told AFP gunmen also assaulted a Houthi checkpoint north of Sanaa with machineguns and rocket-propelled grenades, killing several people late Thursday.

In the Shiite-populated Dhammar province, south of Sanaa, pro-government fighters attacked Houthi headquarters, killing five, tribal sources said.

Meanwhile, the Saudi-led coalition carried out air strikes against a rebel-held army camp in the central city of Baida and hit their positions in oil-rich Marib province in Yemen’s east, witnesses said.

The news broke as the United Nations envoy for Yemen was due to go to Kuwait on Saturday, before spending a week each in Riyadh and Sana’a to discuss a draft peace proposal on Yemen “until we reach a preliminary agreement,” a U.N. spokesman said on Friday.

Ismail Ould Cheikh Ahmed led U.N.-sponsored talks in Geneva on a ceasefire between Yemen’s warring parties that ended a week ago without a deal, as Saudi-led warplanes staged further strikes on the dominant Houthi armed faction and allies.

“He intends to spend more time in the two capitals so as to discuss the draft principles paper developed here in Geneva as he said ‘until we reach a preliminary agreement’,” U.N. spokesman Ahmad Fawzi told a news briefing.