SANAA, Yemen — Two suicide bombers struck in Yemen on Thursday — one targeting a gathering of Shiite rebels in the country’s capital and the other hitting a military outpost in the south — in attacks that killed nearly 70 people, officials said.

The bombings underscored Yemen’s highly volatile situation following last month’s takeover of the capital, Sanaa, by the Shiite Houthi rebels whose blitz stunned the impoverished Arab nation on the southern corner of the Arabian Peninsula. The Houthis’ push into Sanaa also prompted threats of retaliation from their Sunni militant foes in al-Qaida’s Yemen branch.