Several Houthis were killed , dozens wounded in violence Tuesday . - The UN says it is investigating reports of a massacre by the Saudi-led coalition on civilians who fled their homes after airstrikes hit Sanaa's airport. Houthis are protesting oil subsidy reform , current government .
Several Houthis were killed , dozens wounded in violence Tuesday . Interior Ministry says shots came from armed protesters in crowd . Houthis are protesting oil subsidy reform , current government .