Fighting raged through Yemen Sunday, with jets from the Saudi-led coalition attacking Houthi-held positions near the presidential compound in the capital of Sana'a and ground clashes erupting in the southern port city of Aden.
Witnesses reported at least five airstrikes on an arms depot at a military base on the outskirts of Sana'a and at a site near the palace where weapons were being transported.
Meanwhile, other air raids and naval warships targeted Houthis in Aden, with new street fighting between them and troops loyal to President Abd-Rabbu Mansour Hadi, who has fled to exile in Saudi Arabia.
Other fighting erupted in the oil-rich central Marib province. Forces loyal to former President Ali Abdullah Saleh aligned with the Houthis fought tribesmen on the ground while Saudi jets launched airstrikes.
The warplanes also struck pro-rebel sites in Shabwa and Lahj provinces.
The Riyadh-led air bombardment entered its second month Sunday despite Saudi Arabia's announcement last week that it was scaling back its campaign.
The latest airstrikes and ground clashes show how elusive a negotiated peace may be in the Arab world's poorest country.
The United Nations has appointed Mauritanian diplomat Ismail Ould Cheikh Ahmed as the new special envoy to Yemen.
The UN said Ahmed "will work closely with the members of the United Nations Security Council, the Gulf Cooperation Council, governments in the region and other partners, as well as the United Nations country team for Yemen" in an effort to start peace talks.
Saleh has urged Houthi insurgents to heed UN demands to retreat from territory they have seized, but there has been no indication that is occurring.
The UN says that more than 550 civilians have been killed in the Yemeni fighting in the past month, including 115 children.