Saudi Arabia says it is seeking clarification about an explosion that has killed at least 40 people in a camp for displaced people in Yemen.
Humanitarian workers say it appears an airstrike carried out by the Saudi-led coalition against Houthi militia was to blame.
Yemen’s foreign minister earlier blamed Houthi artillery for the blast, but the Saudi military says it is looking into what happened.
Saudi Arabia is leading a coalition of Sunni Muslim countries against Houthi fighters opposed to President Abd-Rabbu Manour Hadi.
Brigadier General Ahmed Asseri, a spokesman for the Saudi-led coalition, said:
“We confirmed from day one that we are working hard to avoid collateral damage.”
Iran, which is allied to the Houthi group, has condemned the airstrikes, but denies it is helping the militia.