SANAA/GENEVA - The Saudi-led coalition killed eight civilians in two separate air strikes on rebel-controlled areas of northern Yemen on Thursday, a government official said.

Warplanes from the coalition, which supports forces loyal to President Abedrabbo Mansour Hadi, hit "by mistake" a vehicle at Razah in Saada province, killing five civilians, said the official.

Another air strike killed three civilians travelling in a vehicle in Shadeh, a village also located in Saada, said the same source.

Saada province is a stronghold of the Iran-backed Shiite Huthi rebels who overran the capital Sanaa in September 2014 before going on to seize other provinces.

Human rights groups accuse the coalition, which has stepped up its strikes against rebel positions especially in northern Yemen, of a string of such attacks that have killed civilians.

On September 22, at least 20 civilians died in coalition air strikes on rebel-held Hodeida, in western Yemen, in what a government official said was a possible "error".

The conflict between Yemen's government and the Huthi rebels escalated in March last year with the intervention of the Arab coalition in support of Hadi's government. More than 6,600 people are estimated to have been killed since then, most of them civilians, according to the United Nations.

Bid for international

 war probe fails at UN

The bid to launch an international probe into the conflict in Yemen failed Thursday, in a defeat for the UN rights chief who demanded an inquiry.

Rights chief Zeid Ra'ad Al Hussein said last month that a fully independent, international investigation was needed to end impunity for a raft of grave violations against the Yemeni people.

A group of European states, led by the Netherlands, then spearheaded a push at the UN Human Rights Council for a resolution setting up an international inquiry. Saudi Arabia, which is leading a military coalition in support of the Yemen's government against Iran-backed Huthi rebels, has been staunchly opposed to such a probe. In the end, the EU-backed resolution was scrapped, leaving only a competing and far milder text on the table, drafted by Sudan.

That resolution, which was adopted without a vote on Thursday, mandated Zeid's office to enhance cooperation with Yemen's own National Commission on the conflict.

Rights groups including Amnesty International have described that commission as feckless, one-sided, and lacking the expertise needed to conduct a credible inquiry.

But before it was adopted, Thursday's resolution was beefed up to say that  while assisting Yemen's own investigation UN experts should be "collecting and preserving information to establish the facts and circumstances of alleged violations and abuses."

Zeid was instructed to provide his own reports on the conflict, presumably using information gathered by his own staff.

"It's a step in the right direction", John Fisher of Human Rights Watch in Geneva told AFP, noting that the resolution "fell short" of the hoped-for inquiry.

Salma Amer, UN Advocacy Officer at the Cairo Institute for Human Rights Studies, said in a statement that the text "puts Saudi Arabia's desire for impunity above the need to protect the people of Yemen."

But speaking on behalf of the EU after the resolution was adopted, Slovenia's representative to the UN in Geneva, Vojislav Suc, described the text as a "good and reasonable compromise."

A similar effort to set up a UN inquiry was withdrawn at the Council last year, under Saudi pressure.

More than 6,600 people, including civilians, have been killed in the Yemeni conflict since the Saudi-led coalition began its air campaign in March 2015, the UN says.

The coalition has been accused of striking hospitals and other civilian targets, while rebel fighters have also been blamed for grave violations.