Cairo — An explosion at a gas station triggered a massive fire in central Yemen, killing at least 15 people, health officials said Sunday. The explosion occurred Saturday at the Zaher district in the province of Bayda, the Houthi rebel-run Health Ministry said in a statement. At least 67 others were injured, including 40 in critical condition. The ministry said rescue teams were searching for those reported missing. It wasn’t immediately clear what caused the explosion. Footage circulated online showing a massive fire that sent columns of smoke into the sky and left vehicles charred and burning. Bayda is controlled