Fears are growing that the Yemen civil war could spiral out of control following the killing of the country’s former president Ali Abdullah Saleh. The longtime Yemeni strongman was brutally assassinated on Monday by Iranian-backed Shiite Houthi rebels, who are fighting a Saudi-led coalition of Sunni countries. A video circulating online showed Saleh’s lifeless body being dumped into a pickup truck by rebels, with whom Saleh had been allied for nearly three years before apparently flip-flopping and offering to enter into negotiations with Riyadh. At the same time, forces loyal to the ex-president became engaged in battles with the rebels in the capital Sanaa, which was overtaken by the Houthis in early 2015, prompting the Saudis to intervene in the conflict on behalf of deposed leader Abdrabbuh Mansour Hadi. The resulting proxy war has pit regional rivals Iran and Saudi Arabia against each other, raising tensions across the region which recently spilled over into Lebanon with the resignation—thereafter retracted—of Prime Minister Saad Hariri. The war in Yemen has already killed some 10,000 people, led to a major cholera outbreak and has left nearly 80 percent of the population—many on the brink of starvation—in dire need of humanitarian aid.