Warplanes from a Saudi-led coalition bombed the Iran-allied Houthi movement across Yemen on Wednesday and dropped weapons to Islamist militias battling the group, a day after being accused of bombing the hospital of an international medical aid charity.

The sorties showed the coalition was determined to use its air power to push back the Houthis, Yemen's dominant group, despite charges by Medecins Sans Frontieres (MSF) that coalition bombing destroyed one of its hospitals late on Monday. The alliance has denied the charges.

Saudi Arabia and other Gulf Arab countries have been bombing the Houthis and their army allies loyal to ex-president Ali Abdullah Saleh since late March.

At least 5,600 people have been killed, but the alliance has made little headway in restoring Yemen's exiled government to the Houthi-controlled capital, Sanaa.

The coalition dropped weapons in the southwestern city of Taiz, Yemen's third largest which has become a major front in the coalition's northward push toward the capital. Islamist militias are fighting artillery and heavy machine gun duels with the Houthis in civilian neighborhoods there.