The UN reported on Friday about a number of Somali refugees that were killed when their boat was hit in an air strike off the coast of Yemen.
At least 31 people died in the incident, which happened late on Thursday, news agencies reported, quoting officials in Hudaydah port.
The vessel was attacked near the Bab al-Mandeb strait. Women and children were among those killed.
Coastguard Mohamed al-Alay said the refugees, carrying official UNHCR documents, were travelling from Yemen to Sudan when they were attacked by an Apache helicopter near the Bab al-Mandeb strait.
A sailor who had been operating the boat, Ibrahim Ali Zeyad, said 80 refugees had been rescued after the incident.
It was not clear who carried out the attack. The port is controlled by Houthi rebels who are fighting a Saudi-led coalition in Yemen's two-year war.
The International Organization for Migration’s spokesman, Joel Millman, told a UN news briefing in Geneva that he was unable to confirm news reports indicating that an Apache helicopter strike was responsible for the attack.
“Our confirmation is that there are dozens of deaths and many dozens of survivors brought to hospitals,” he said.
The incident occurred amid concerns that the Saudi-led coalition is preparing to launch a wider operation against the port city.