More than 2,500 Yemeni households, an estimated 16,000 people, were displaced by conflict between Houthi rebels and the Saudi-backed, internationally-recognized government in the provinces of Marib, Hodeidah and Taiz in January alone, according to the International Organization for Migration.

The total number of internally displaced in war-torn Yemen has risen to 4.2 million following seven years of war between the Iran-backed Shiite rebels, who control the capital Sana’a, and the government of Abdrabbuh Mansur Hadi, the United Nations refugee agency (UNHCR) has said.

The war has left 80% of the country’s 30 million people in urgent need of aid as the country witnesses the worst humanitarian crisis in the world, according to the UN.

The Saudi Arabia-led coalition began its aerial campaign against the Houthi rebels in 2015.