The United Nations Children’s Fund (UNICEF) warned on Friday that millions of Yemeni people are at risk of famine as a result of the country’s years-long military conflict and sharp deterioration of its economy, calling for urgent action.

“Children in Yemen are starving not because of a lack of food, but because their families cannot afford food,” the UNICEF said in a statement posted on Twitter.

The UN organization said that “the impact of the economic collapse on the humanitarian crisis in Yemen cannot be understated.”

“Without urgent action, millions could be plunged into famine,” it warned.

According to the UNICEF mission in Yemen, nearly 400,000 children under the age of five are slipping from acute malnutrition to severe acute malnutrition.

Yemen has been mired in a civil war since late 2014 when the Iran-backed Houthi militia seized control of several northern provinces and forced the Saudi-backed Yemeni government of President Abd-Rabbu Mansour Hadi out of the capital Sanaa.

The UN is trying to end the civil war that has killed tens of thousands of people, displaced 4 million people, and brought the country to the brink of famine.