Yemeni children are seen at their shelter at a displaced camp in Sanaa, Yemen, Feb. 29, 2020. (Photo: Xinhua)

A Yemeni girl sits outside her family's shelter at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni man sits outside his shelter at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni man sits inside his shelter at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni family wait to get their breakfast at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni mother holds her child outside their shelter at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni girl stands by her elder sister at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni girl stands at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

Yemeni people sleep outside their shelter at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni girl carries her little brother at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni child pushes his tricycle at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

A Yemeni child stands inside a shelter at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.

Yemeni children wait to get their breakfast at a displaced camp in Sanaa, Yemen, Feb. 29, 2020.