Yemeni fighter Hassan Saleh backed by the Saudi-led coalition stands for a photograph after clashes with Houthi rebels on the Kassara front line near Marib, Yemen, Sunday, June 20, 2021. Saleh and his younger brother Saeed, both in their early 20s, both in their early 20s, have been fighting alongside other government fighters and tribesman outside the oil-rich city of Marib against the months-long offensive by the Iranian-backed rebels. They say they need more weapons to push the attackers back. (Photo by Nariman El-Mofty/AP Photo)





Yemeni fighters drive their damaged armored vehicle with a poster of a commander brigadier general and Arabic that reads, “martyr commander brigadier general Self Abd al-Rab al-Shadady”, who was killed in clashes with Houthi rebels, on the Mass front line, in Marib, Yemen, Saturday, June 19, 2021. On the most active front line in Yemen's long civil war, the months-long battle for the city of Marib has become a dragged-out grind with a steady stream of dead and wounded from both sides. (Photo by Nariman El-Mofty/AP Photo)





Yemeni fighter Hassan Saleh, left, identifies a target for a fighter during clashes with Houthi rebels on the Kassara front line near Marib, Yemen, Sunday, June 20, 2021. On the most active front line in Yemen's long civil war, the months-long battle for the city of Marib has become a dragged-out grind with a steady stream of dead and wounded from both sides. (Photo by Nariman El-Mofty/AP Photo)





A man walks in a mass graveyard where hundreds of Yemeni fighters are buried in Marib, Yemen, Monday, June 21, 2021. (Photo by Nariman El-Mofty/AP Photo)





Shops are open for business in Marib, Yemen, Monday, June 21, 2021. (Photo by Nariman El-Mofty/AP Photo)





Smoke rises from a Houthi missile attack near the Kassara front line during clashes with Yemeni fighters backed by the Saudi-led coalition, in Marib, Yemen, Sunday, June 20, 2021. (Photo by Nariman El-Mofty/AP Photo)





Banners show Yemeni fighters who were killed in clashes with Houthi rebels, on a street in Marib, Yemen, Sunday, June 20, 2021. (Photo by Nariman El-Mofty/AP Photo)





Gamila Salih Ali, right, and Ahmed Farag, mother and uncle of two-year-old Liyan Taher, seen in poster at left, who was killed with her father 32-year-old Taher Farag, seen in poster at right, in a ballistic missile and an explosive-laden drone fired by Yemen's Houthi rebels that hit a fuel station on June 5, 2021 in Rawdha neighborhood, show a poster with photos of them at their home in Marib, Yemen, Saturday, June 19, 2021. (Photo by Nariman El-Mofty/AP Photo)





An aerial view taken on June 6, 2021 shows the Well of Barhout known as the “Well of Hell” in the desert of Yemen's Al-Mahra province. Closer to the border with Oman than to the capital Sanaa 1,300 kilometres (800 miles) away, the giant hole in the desert of Al-Mahra province is 30 metres wide and thought to be anywhere between 100 and 250 metres deep. Local folklore says it was created as a prison for the demons – a reputation bolstered by the foul odours rising from its depths. (Photo by AFP Photo/Stringer)





Yemeni fighters backed by the Saudi-led coalition ride on the back of an armored vehicle as they leave the front lines of Marib, Yemen, Saturday, June 19, 2021. (Photo by Nariman El-Mofty/AP Photo)





Yemeni fighters backed by the Saudi-led coalition ride in a truck on the Kassara frontline near Marib, Yemen, Sunday, June 20, 2021. (Photo by Nariman El-Mofty/AP Photo)





A Yemeni fighter backed by the Saudi-led coalition looks at damage to the back of an armored vehicle as they leave the front lines near Marib, Yemen, Saturday, June 19, 2021. (Photo by Nariman El-Mofty/AP Photo)





A 19-year-old Yemeni fighter backed by the Saudi-led coalition rides on the back of an armored vehicle on the way to the front lines on the outskirts of Marib, Yemen, Saturday, June 19, 2021. (Photo by Nariman El-Mofty/AP Photo)





A Yemeni fighter backed by the Saudi-led coalition rides on the back of an armored vehicle as he leaves the front lines of Marib, Yemen, Saturday, June 19, 2021. (Photo by Nariman El-Mofty/AP Photo)





Children riding on donkeys queue to fill their jerrycans with water from a cistern at a make-shift camp for the internally displaced in Yemen's northern Hajjah province on July 12, 2021, amidst an extreme heat wave and severe water shortage. (Photo by Essa Ahmed/AFP Photo)





Youths watch as one jumps from a bridge across a flooded drainage canal following heavy rainfall in the old city of Yemen's capital Sanaa on August 3, 2021. (Photo by Mohammed Huwais/AFP Photo)





A Yemeni boy wades and attempts to traverse a flooded street following heavy rainfall in Sana'a, Yemen, 23 July 2021. Heavy rainfall and a​ssociated floods have hit several cities of Yemen over the past few days. (Photo by Yahya Arhab/EPA/EFE)





Displaced Yemeni children shield themselves from the sun at a camp for Internally Displaced Persons (IDPs) on the outskirts of Sana'a, Yemen, 07 August 2021. Some 8.1 million children in Yemen need emergency educational assistance compared to the 1.1 million children before the war broke out in the Arab country in 2015, the United Nations Children’s Emergency Fund (UNICEF) has explained. Over two million school-age children in Yemen do not get to go to school due to the war. (Photo by Yahya Arhab/EPA/EFE)





Sulaiman Jubran uses an axe to cut a tree in Khamis Banisaad district of al-Mahweet province, Yemen, June 10, 2021. “Demand depends on the number of fuel ships that make it to Hodeidah port. These days it (demand) is very high”, said Jubran, who scratches a living selling firewood to visiting traders. “We are scared the country will become a desert, it is already happening . you no longer see the trees that once covered the mountains”, he said. (Photo by Khaled Abdullah/Reuters)





A girl looks on as she leads her cow across a spring lake in Khamis Banisaad district of al-Mahweet province, Yemen, June 23, 2021. (Photo by Khaled Abdullah/Reuters)