The Saudi-led Arab coalition launched air strikes on targets controlled by the Houthi group in several provinces in Yemen overnight, officials and residents said Wednesday.The campaign led by Saudi Arabia is against the Houthi group and forces loyal to former President Ali Abdullah Saleh since late March at the request of the exiled Yemeni government.

The fresh air raids hit the runway of civilian and military airports of al-Hodayda city in western Yemen. In northwestern province of Hajja, warplanes pounded the headquarters of Brigade 25 Mika, which is under control of Saleh's forces in Abbs district near the border with Saudi Arabia, after Houthi fired missiles toward Saudi military sites, local officials said.

In provinces of Aden, Taiz, Lahj and Marib, Houthi-controlled military camps were also targeted, according to local officials.

Residents in southern province of al-Bayda said at least ten Houthi fighters were killed in the air strike while they gathered after seizing the governmental complex in Mukairas district on Tuesday night.

Meanwhile, battles between Houthis and local tribal resistance continued on the ground early Wednesday in provinces of Aden, al-Dhalee and Taiz.

The warring factions used machine guns and mortar shells to attack each other, causing damage to civilian houses. Medic sources said dozens of people were wounded in the battles.

Following the collapse of Geneva talks, the United Nations appealed for 1.6 billion US dollars to help more than 21 million Yemenis, or 80 percent of the population, in need of aid, warning of a "looming catastrophe" in the war-torn country.

In addition, thousands of suspected cases of the mosquito-borne viral infection Dengue fever have been reported in Yemen, where a major health crisis is unfolding, the World Health Organization (WHO) announced Tuesday.

It said that more than 3,000 suspected cases of Dengue had been reported in Yemen since March 20 with some non-governmental organizations flagging more than 6,000 cases.

Dengue fever is a severe, flu-like illness that affects infants, young children and adults, but seldom causes death, according to the WHO, which says early detection and access to proper medical care lowers fatality rates.