Saudi Arabia has vowed to donate $1.5bn - half of the UN's humanitarian appeal for Yemen - which has been largely devastated by years of war. But as the conflict continues, the situation is also deteriorating in areas controlled by the Saudi-backed government. In the southern port city of Aden, secessionists say they want to overthrow the internationally-recognised government. Al Jazeera's Osama Bin Javaid reports from Aden. - Subscribe to our channel: Thanks to AlJazeeraEnglish