UNITED NATIONS, United States - UN Chief Ban Ki-moon has repeated his call for all sides in the conflict in Yemen to "immediately cease all hostilities," following a devastating series of raids resulting in numerous civilian deaths and injuries.

In a statement on Wednesday, Ban urged "all parties to the conflict to immediately cease all hostilities and for the Yemeni parties to return to direct talks facilitated by his special envoy for Yemen."

He reminded all parties "of the utmost necessity to protect civilians and to respect their obligations under international humanitarian law."

Ban condemned a reported airstrike that hit east of Sanaa in Nehm, killing at least nine civilians.

He also denounced attacks, which appeared to come from Yemen, which were said to have killed at least seven civilians when a workshop was hit Tuesday in Najran, Saudi Arabia.

That blow caused Saudi Arabia’s worst civilian death toll in the kingdom’s south since the Arab coalition intervened in Yemen in March 2015.

"Civilians, including children, are paying the heaviest price in the ongoing conflict, as civilian infrastructure, such as schools and hospitals, continue to be hit," he said.

Ban expressed alarm at "the escalation of airstrikes and ground fighting in Yemen and along the Saudi Arabia-Yemen border" since the suspension in early

August of UN-brokered peace talks in Kuwait.

The United Nations says more than 6,500 people, mostly civilians, have been killed since last March and more than 80 percent of the population needs humanitarian aid. — AFP