At least 70 people died and 138 others were wounded in an airstrike on a prison in northern Yemen, Doctors Without Borders (MSF) said on Friday.
"Last night Sa'ada City Remand Prison was hit by what was reported to be an air strike from the Saudi-led Coalition. Al-Gumhourriyeh Hospital in the city has received 138 wounded and 70 dead. They are so overwhelmed that they can't take any more patients," MSF said on Twitter.
The group added that there were also airstrikes in the Yemeni capital Sanaa last night, including at the airport.
"We have received reports of air strikes in many other governorates across the north of Yemen. Since this morning the internet has been completely cut off," it added.
Yemen has been engulfed by violence and instability since 2014, when Iran-aligned Houthi rebels captured much of the country, including Sanaa.
A Saudi-led coalition aimed at reinstating the Yemeni government has worsened the situation, causing one of the world's worst man-made humanitarian crises, with nearly 80% or about 30 million people needing humanitarian assistance and protection and more than 13 million in danger of starvation, according to UN estimates.