Saudi Deputy Crown Prince Mohammed bin Salman - who is also the kingdom's defense minister - ordered the delivery of cargo planes carrying humanitarian goods to Yemen's government-held southern city of Aden, Al Arabiya News Channel reported on Thursday. The deputy crown prince issued the order following directions from King Salman bin Abdulaziz. The delivery planes, which arrive at the newly-reopened airport of Aden, belong to the Royal Saudi Air Force. They aim at bringing much-needed relief to Yemeni citizens who have been suffering from the violations of the Iranian-backed Houthi militias. On Wednesday, a Saudi military aircraft landed at Aden airport becoming the first plane to reach the port city in four months. Some 12.9 million people in Yemen are either "food insecure" or "severely food insecure," according to World Food Program (WFP) estimates.