The Saudi-led coalition fighting in Yemen must do more to address "very serious concerns" about the killing of children, UN Secretary-General Ban Ki-moon said Tuesday, as he weighs whether to return the alliance to a blacklist of child rights violators.

Ban reported to the Security Council on his controversial decision to temporarily remove the coalition from the UN list of shame pending a review, triggering an outcry from rights groups.
"I still have very strong concerns about the protection of Yemeni children. They must always come first," Ban said, adding that the United Nations was continuing its review with the Saudi-led coalition.
Saudi Arabia reacted angrily to the decision in June to blacklist the coalition after a UN report found the military alliance was responsible for 60 percent of the 785 children's deaths in Yemen last year.
Last week, Saudi Arabia outlined in a 13-page confidential letter to Ban the measures that the coalition is taking to prevent civilian deaths.
In the letter obtained by AFP, Saudi Ambassador Abdallah al-Mouallimi offered to share with the United Nations the results of 10 investigations of air strikes on hospitals, homes, a wedding party and markets.
The coalition will share the results of the investigations with the United Nations during a meeting they have proposed be held in Riyadh, he said.
Ban told the council he had received information on the measures taken by the coalition, but that these fell short.
"We will continue our engagement to ensure that concrete measures to protect children are implemented," he told the council.
Ban emphasized that "the content of the report stands."
In his letter, the Saudi ambassador said the coalition had set up a reparations committee to consider compensation for the victims and opened a direct dialogue with aid organizations to guarantee the protection of hospitals.
Mouallimi provided details of steps taken to designate targets and ensure they have "identifiable military purposes."
They include drawing up a list of prohibited targets such as schools and diplomatic missions and working with "local forces to identify and vet targets for airstrikes."
Ban in June said he was forced to remove the coalition from the list after Saudi Arabia threatened to cut off funding of UN aid programs. Riyadh denies the accusations.
The coalition launched an air campaign in support of Yemen's President Abedrabbo Mansour Hadi in March 2015 to push back Huthi rebels after they seized the capital Sanaa and many other parts of the country.
The war has killed some 6,400 people and exacerbated the humanitarian crisis in the impoverished country, the United Nations says.