Warplanes attack air base near Yemen's Aden

A malnourished child lies in a bed at a hospital in Yemen's capital Sanaa July 28, 2015. REUTERS/Khaled Abdullah

SANAA/ADEN (Reuters) - Warplanes attacked Houthi militia in control of Yemen's largest air base north of Aden on Tuesday, seeking to expand territorial gains made by Saudi-led coalition forces since they captured the southern port city last week.

Witnesses said big explosions were heard at the al-Anad base, 50 km (30 miles) from Aden, which has been held by the Iranian-allied Houthi movement for much of a fourth-month-old civil war and commands the approaches to Aden.