Yemeni officials said several women and children were among the casualties.
The United Nations High Commissioner for Refugees (UNHCR) said it was "deeply shocked and saddened at reports of the deaths and injuries of a number of internally displaced persons in an aerial attack" on the area.
Yemen's government, allied with a Saudi-led Arab military coalition, has for years been battling Iran-backed Shiite Houthi rebels for control of the impoverished country.
"It also illustrates the difficulties in the delivery of humanitarian protection and assistance in Yemen..."
Unusually in Yemen's fractured political landscape, Islah has supporters in the north and south of the country.Since the Saudi-led coalition intervened in Yemen in 2015, Islah has tried to distance itself from the Brotherhood, in deference to the government-in-exile's Saudi hosts.
"If there is no accountability, if groups that are fighting think they can use their political influence - and if they're powerful enough and rich enough, then they can get away with killing and injuring children, or bombing schools and hospitals - it sets a really unsafe precedent not just for Yemen but for conflicts around the world", Anning said.
Separately, UN officials said the coalition barred one of its flights to Yemen's Houthi-controlled capital, Sana'a.
A total of 1,802 people have been killed by a cholera outbreak in war-torn Yemen since late April, the World Health Organization (WHO) said Tuesday.
Haq said the United Nations humanitarian air service had been allowed to take off on Wednesday and had landed in Sana'a carrying 26 humanitarian aid workers, but not the three journalists from the British Broadcasting Corporation.
The plane was going to bring aid workers and BBC reporters from Djibouti.
According to Save the Children, over 4,000 children have been killed or injured as a direct outcome of the conflict, while half a million children are estimated at risk of dying from malnutrition.