SANA, Yemen — Airstrikes by a Saudi-led military coalition were said to have killed at least 80 people in Yemen on Wednesday, and the World Health Organization warned that roughly one-third of the country’s population was in urgent need of medical care.

The airstrikes hit a military base in a densely populated neighborhood here in the capital and areas near the Saudi border. Health officials said those killed included dozens of civilians, as well as fighters loyal to the Houthi rebel movement.

The death toll, which could not be independently confirmed, appeared to be one of the highest in a single day since Saudi Arabia launched its air war against the Houthis in late March, with the stated goal of returning Yemen’s exiled government to power.