Saudi-led air strikes targeting a military camp killed eight civilians in the central Yemeni city of Taiz on Sunday, a medical source said.
The air raids were aimed at a site held by soldiers loyal to former Yemeni President Ali Abdullah Saleh who have joined up with Iranian-allied Houthi rebels against local militias in the south, the source said.
Saudi Arabia and its Sunni Arab allies began air strikes against the Houthis more than two weeks ago, hoping to halt their advance towards the southern port city of Aden.
Saleh remains highly influential despite having given up power in 2012 after mass protests against his rule and troops loyal to him back the Houthis.
The campaign has raised fears that a sectarian proxy war between rivals Riyadh and Tehran will further destabilise the Middle East and potentially destroy the Yemeni state.
In a sign of the military's weakening control, suspected Al Qaeda militants killed an army colonel in the central Shabwa province on Sunday, a local official said.
Separately, an al Qaeda leader was killed in an apparent U.S. drone strike on a group of militants west of the port city of Mukalla on the Arabian Sea, said residents.
It was the first reported drone strike against the powerful Yemeni branch of the global militant group since the U.S. evacuated about 100 special forces troops advising Yemeni forces last month.
While the United States and its Sunni Gulf allies are worried about the threat from Sunni radicals such as al Qaeda, they also fear the war will increase the influence of Shi'ite Iran.
Saudi Arabia is concerned its war on the Houthis could spill over the border, but Iran has denied Saudi allegations that it has provided military support to the group.
The Houthis also deny getting help from Iran and say their armed campaign is designed to stamp out corruption and Sunni al Qaeda militants.
According to the United Nations, the conflict, in which the Houthis seized the capital Sanaa in the north in September, has killed 600 people, wounded 2,200 and displaced 100,000 others.
Saudi Arabia's Defence Ministry has said more than 500 Houthis have also been killed in fighting on Yemen's border, but has not said how it arrived at that figure.
Yemen on the brink
Who are fighting whom?
- ›Houthis: The rebel group controls nine of 21 provinces now
- ›Saudi-led coalition: Here are some of those who are participating and what they are deploying: Saudi Arabia: 100 fighter jets, 150,000 soldiers and some naval units UAE: 30 fighter jets Bahrain: 15 fighter jets Kuwait: 15 fighter jets Qatar: 10 fighter jets Jordan: 6 fighter jets Sudan: 3 fighter jets Egypt: naval and air forces involved.
- ›Yemeni security forces: The military is now split as units that support Mr. Hadi, units that support the Houthis, and units that support a still-influential Saleh, who is in the Houthi camp for now
- ›Popular Resistance Committees: Militia loyal to Hadi in his stronghold of south Yemen.
- ›AQAP: Mr. Hadi and Houthis are fighting al-Qaeda in the Arabian Peninsula, which has staged several attacks in the country and is strong in the south. Active since 2009. AQAP has taken advantage of the power struggle.
- ›IS: A new group of militants inspired by the Islamic State group has claimed major attacks, including suicide bombings which killed at least 142 people at Shia mosques in Sana’a.
- ›U.S.: CIA drones have continued to target top AQAP leaders, but the campaign has suffered from Mr. Hadi’s absence. Last week, U.S. military advisers were withdrawn from a southern base as al-Qaeda militants seized a nearby city.
Who are the Houthis?
The Houthis are followers of the Shia Zaidi sect, the faith of around a third of Yemen’s population. Officially known as Ansarallah (the partisans of God), the group began as a movement preaching tolerance and peace in the Zaidi stronghold of North Yemen in the early 1990s.
After some protests pitted it against the government, the group launched an insurgency in 2004 against the then ruler Ali Abdullah Saleh that lasted till 2010. Their opponents view them as a proxy of Shia Iran. The group is hostile to the United States but has also vowed to eradicate al-Qaeda. They participated in the 2011 Arab Spring inspired revolution in Yemen that replaced Saleh with Abdrahbu Mansour Hadi.
Key dates to the Yemen conflict
- ›September 21, 2014: Houthi rebels seize government and military sites in Sana’a after several days of fighting that killed more than 270 people. Rival groups sign a U.N.-brokered peace deal stipulating a Houthi withdrawal from the capital and formation of a new government.
- ›October 9, 2014: Al-Qaeda in the Arabian Peninsula, which has declared war on the Houthis, claims an attack in Sana’a in which 47 are killed.
- ›October 14, 2014: The Houthis seize the Red Sea port of Hodeida, 230 km west of Sana’a, then move toward the centre without opposition from government forces but face fierce resistance from AQAP and its tribal allies.
- ›January 20, 2015: Houthis attack Mr. Hadi’s residence and seize the presidential palace, and the President and Prime Minister resign two days later.
- ›February 6, 2015: The rebels announce they have dissolved Parliament and installed a presidential council to run the country. The United States and Gulf monarchies accuse Iran of backing the Houthis. In the south and southeast, authorities reject what they brand a coup attempt.
- ›February 21, 2015: Mr. Hadi flees south to Aden after escaping from weeks under house arrest and urges the international community to “reject the coup,” rescinding his resignation and subsequently declaring Aden the temporary capital.
- ›March 19, 2015: Clashes in which at least 11 are killed force the closure of the international airport in Aden and Mr. Hadi is moved to a more secure location after an air raid on the presidential palace there.
- ›March 22, 2015: The Houthis advance southwards, seizing the airport and a nearby military base in Taez, north of Aden and a strategic entry point to Mr. Hadi’s stronghold. Houthi leader Abdelmalek al-Houthi says the rebels have moved south to combat Al-Qaeda and the Islamic State group.
- ›March 25, 2015: Mr. Hadi is again moved as rebel forces bear down on Aden, capturing a major airbase nearby just days after U.S. military personnel were evacuated from it.
