At least 42 Somali refugees have been shot dead by a helicopter gunship while on board a boat off the coast of Yemen.
The refugees, who included children, were hit in waters 30 miles off the southern coastline of Shia rebel-held Hodeida province, according to a Yemeni trafficker who survived the attack.
Al-Hassan Ghaleb Mohammed told the Associated Press news agency the refugees were trying to reach Sudan after leaving Ras Arra.
He said the refugees held up flashlights in an attempt to show they were migrants. The helicopter then stopped firing, he said, but only after dozens had been killed.
Laurent De Boeck, head of the International Organisation for Migration in the rebel-held Yemeni capital, Sanaa, told the Associated Press 77 survivors were taken to a detention centre in Hodeida.
Mr De Boeck added the UN agency believes all those on the boat were registered refugees, and it is in contact with the hospital, clinics, and the detention centre to provide medical care.
The UN Refugee Agency said it was "appalled by this tragic incident, the latest in which civilians continue to disproportionately bear the brunt of conflict in Yemen."
Yemen's Shia rebels accused the Saudi-led air coalition of carrying out the attack. The coalition, which in turn accuses the rebels of smuggling weapons in small boats, has been heavily bombarding the coast around Hodeida.
Despite more than two years of fighting, African migrants continue to arrive in Yemen, where a lack of central authority means they are free to travel onwards to Saudi Arabia.
More than 111,500 migrants travelled to Yemen last year, up from around 100,000 the year before, according to the Regional Mixed Migration Secretariat.
The war has left migrants vulnerable to armed trafficking rings, which are thought to be connected to the groups involved in the conflict.
The Houthi movement - which champions Yemen's Zaidi Shia Muslim minority - is engaged in conflict with coalition troops and pro-government fighters, who are trying to advance northward to stop them taking control of Red Sea ports.
The conflict began when the Shia Houthis, supported by former president Ali Abdullah Saleh and allies, seized the capital, Sanaa, in September 2014, overthrowing Saudi-backed President Abed-Rabbo Mansour Hadi's government.