The Yemeni rebels' media office said hundreds have been injured in the airstrike, while rescuers are still searching for bodies and survivors in the rubble of the prison site.

According to reports, the Houthi rebels used the prison, which came under attack, to hold detained migrants, mostly Africans, attempting to cross through the war-torn country into Saudi Arabia.

Screen-grab from Youtube video posted by France 24

International humanitarian medical NGO, Doctors Without Borders, reported that more than 200 people had been wounded in Friday's airstrike which was a part of the escalating air and ground offensive in Yemen’s yearslong civil war.

On Friday, a Saudi-led coalition's airstrike hit a detention centre run by Houthis in Saada, a stronghold of the rebel Houthi movement in north-western Yemen.

Condemning the airstrike on Yemen prison, UN Secretary General Antonio Guterres said in a statement that the "escalation needs to stop".

"Deeply shocking reports from Yemen of intensifying airstrikes in populated areas by the Saudi-led coalition destroying or damaging civilian infrastructure, including a prison in Sa’ada with many casualties feared. The cost in human lives is unacceptable," UN Human Rights' tweet read.

Meanwhile, Saudi coalition spokesman Brig. Gen. Turki al-Malki claimed that the Houthis had not reported the site as needing protection from airstrikes to the United Nations or the International Committee of the Red Cross.

The spokesperson said the Houthis’ failure to do so represented the militia’s “usual deceptive approach” in the conflict.

The attack came four days after three people were killed in a 'suspected drone attack' claimed by Houthi rebels that triggered an explosion and a fire at two locations in United Arab Emirates' (UAE) Abu Dhabi.

Image of January 17's suspected drone attack in Abu Dhabi, screen-grabbed from Twitter video

Iran-backed Houthis, a Zaydi Shiite movement, has been fighting against a Saudi-led coalition of Gulf States since 2015 to maintain government control of Yemen.

Tens of thousands of civilians, including more than 10,000 children, have been killed or injured as a direct result of the year-long conflict.