African migrants were among at least 20 civilians killed this week in two attacks on a market in northern Yemen where migrants are known to congregate as they make their way to wealthy Gulf states in search of a better life, the United Nations said.

The UN statement, issued on Thursday, did not specify the type of attacks on Al-Raqw market in Saada province, near the Saudi border, or say who was responsible, but said many of those killed or wounded were Ethiopians.

A Saudi-led military coalition has been battling the Iran-aligned Houthi movement in Yemen for nearly five years in a conflict that has killed tens of thousands of people and pushed millions to the brink of famine.

An aid worker told Reuters there had been an air strike on the market on November 20, followed a week later by artillery shelling. Many migrants pass by the market as they try to reach neighboring Saudi Arabia.

The UN statement said the first attack had killed 10 people and that a similar incident a week later killed 10 and injured 22, including four children.