A van drives past a damaged building in the war-torn southwestern city of Taiz, Yemen August 17, 2016. [Photo/Agencies]

UNITED NATIONS - UN Secretary-General Ban Ki-moon said on Wednesday that civilians including children are paying the heaviest price in the ongoing conflict in Yemen as schools and hospitals continue to be hit.

The statement came days after attacks on a school in northern Yemen and a hospital in the country's northwest province, which have killed dozens of civilians and children.

Ban also condemned the latest attack on a workshop in Saudi border city Najran on Tuesday which killed seven civilians as well as another airstrike hit a home in Nehm, east of Yemeni capital Sanaa, which killed at least nine people, according to the statement.

In this regard, He called on all parties to the conflict to immediately cease hostilities and for the Yemeni parties to return to direct talks.

Yemen has been locked in a civil war since the Houthis seized power and overturned the Yemeni government in late 2014.

Saudi Arabia and its allies intervened to support the exiled Yemeni government in 2015, but failed to bring it back to power in the rebel-held capital Sanaa. The war and ensuing airstrikes have killed over 6,400 people, mostly civilians.