Fifteen bodies and 30 wounded were taken to Haradh Hospital, where MSF operates, near the Al-Mazrak camp in Hajja province, said the manager of the MSF programme in the Middle East, Pablo Marco.

"It was an air strike," he said, adding that it was likely that "more dead are at Al-Mazrak camp".

The UN Office for the Coordination of Humanitarian Affairs (OCHA) also said the camp had been hit.

Arab coalition warplanes, led by Saudi Arabia, have been pounding yemen for the past five days.

The camp has since 2009 been housing Yemenis displaced by the conflict between displaced and the central government.

The MSF official said 500 new families had arrived at the camp over the past two days.

More than 170 people killed in Saudi-led airstrike.