Reports from northern Yemen say more than 80 refugees have been killed in air raids.
The refugees had been displaced by fighting between government forces and Shia rebels.
A New York-based group, Human Rights Watch, wants a full investigation into the incident, which reports say happened on Wednesday.
However, the BBC reports that Yemeni officials deny there was a refugee camp in the area and claim the army had struck only rebels and their supply lines.
An official said the rebels had been shooting from the area before the attack.