UNITED NATIONS (Reuters) - A Saudi Arabia-led military coalition was responsible for an “unacceptably high” 51 percent of child deaths and injuries in Yemen last year, according to a draft United Nations report seen by Reuters on Thursday.

FILE PHOTO: People walk at the site of a Saudi-led air strike in Yemen's capital Sanaa September 21, 2015. REUTERS/Khaled Abdullah

The draft report on children and armed conflict, which still has to be approved by U.N. Secretary-General Antonio Guterres and is subject to change, blamed the Saudi-led coalition for more than 680 child casualties and three-quarters of the attacks on schools and hospitals in Yemen.

“Attacks carried out by air caused over half of all child casualties, with at least 349 killed and 333 injured,” the draft report found. The Saudi-led coalition began an air campaign in Yemen in March 2015 to defeat Iran-allied Houthi rebels.

It will be up to Guterres to decide whether to return the Saudi-led coalition to a child rights blacklist annexed to the report. The coalition was briefly added last year and then removed by then-U.N. chief Ban Ki-moon pending a review.

At the time, Ban accused Saudi Arabia of exerting “unacceptable” undue pressure after sources told Reuters that Riyadh threatened to cut its funding of U.N. programs. Saudi Arabia denied threatening Ban.

The Saudi-led coalition had been named on the blacklist last year after the U.N. report blamed it for 60 percent of child deaths and injuries in Yemen in 2015 and half the attacks on schools and hospital.

Saudi Arabia’s U.N. mission said in a statement on Wednesday that there was “no justification whatsoever” for including the coalition’s name on the blacklist. It declined to comment on the findings in the draft report for 2016.

The report, which officials say is likely to be published next month, is issued in Guterres’ name but was drafted by his special envoy for children and armed conflict, Virginia Gamba. It is produced at the request of the U.N. Security Council.

“The United Nations was informed of measures taken by the coalition in 2016 to reduce the impact of conflict on children,” according to the draft report. “However, despite these measures, grave violations against children continued at unacceptably high levels in 2016.”

The draft report said the Houthi rebels and affiliated forces were responsible for nearly a third of the total 1,340 child casualties verified by the United Nations.

U.N. spokesman Farhan Haq said Guterres received a draft of the 2016 report this week and was due to discuss it with Gamba on Friday. “It’s still a work in progress,” Haq said.