Yemen air strikes
A huge fireball erupts during an air strike on an army weapons depot on a mountain overlooking Yemen's capital Sanaa Khaled Abdullah Ali/Reuters file photo

A UN official has said the Saudi-led coalition against Shiite Houthis in Yemen violates international humanitarian law.

Condemning the military campaign, the UN Humanitarian Coordinator for Yemen Johannes van der Klaauw said the air strikes have pushed civilians into "traps".

"The indiscriminate bombing of populated areas, with or without prior warning, is in contravention of international humanitarian law. Many civilians are effectively trapped in Saada as they are unable to access transport because of the fuel shortage. The target of an entire governorate will put the countless civilians at risk."

Rights groups and monitors have said civilians are unable to flee the conflict-ridden northern Yemeni city of Saada, where support for the Houthis remains strong.

Expressing concern over the situation, the UN envoy said Saada is "where scores of civilians were reportedly killed and thousands were forced to flee their homes after the coalition declared the entire governorate a military target".

Though scaled down, the Saudi-led coalition, mostly comprising Sunni powers, has been pounding Houthi targets. On Saturday, 9 May the coalition said it has conducted 130 air strikes in a 24-hour period.

Hospitals and schools which were used by Houthi rebels to store weapons have been targeted in the air strikes, said Saudi military spokesperson Brigadier General Ahmed Asiri.

Bases of Houthi leaders were also targeted across the Yemeni provinces of Saada and Hajja, added the spokesperson for the coalition. Local reports say the Saudi forces were bombing the rebel chief Abdul Malik al-Houthi's hometown of Marran.