An airstrike by the Saudi-led coalition in Yemen hit a detention facility operated by Houthi rebels, killing at least 82 people and marking yet another sign in the escalating and spreading conflict.

The airstrike in northern Saada province Friday was part of an intense air and ground offensive that marked an escalation in Yemen’s yearslong civil war. The conflict pits the internationally recognized government, aided by the Saudi-led coalition, against the Iranian-backed rebels.

Internet access in the Arab world’s poorest country meanwhile remained largely down as the coalition continued airstrikes on the capital of Sanaa and elsewhere.

The escalation comes after the Houthis claimed a drone and missile attack that struck inside the United Arab Emirates’ (UAE) capital Abu Dhabi earlier in the week. It also comes as government forces, aided by UAE-backed troops and airstrikes from the coalition, have reclaimed the entire province of Shabwa from the Houthis and pressured them in the central province of Marib. Houthis there have for a year attempted to take control of its provincial capital.

Ahmed Mahat, head of Doctors Without Borders (MSF), a charity mission in Yemen, told The Associated Press (AP) they counted at least 82 dead and more than 265 wounded in the airstrike.

The Houthis’ media office said rescuers were still searching for survivors and bodies in the rubble of the prison site in the province of Saada on the border with Saudi Arabia.

Saudi coalition spokesman Brig. Gen. Turki al-Malki alleged the Houthis hadn’t reported the site as needing protection from airstrikes to the U.N. or the International Committee of the Red Cross (ICRC). He claimed the Houthis’ failure to do so represented the militia’s "usual deceptive approach" in the conflict.

The Houthis used the prison complex to hold detained migrants, mostly Africans attempting to cross through the war-torn country into Saudi Arabia, according to the humanitarian organization Save the Children.

But Mahat, of Doctors Without Borders, said the airstrike hit a different part of the facility housing other types of detainees. "The migrants there are safe," he said.

Al-Malki said reports that the coalition targeted the prison were inaccurate and that the coalition would correspond "facts and details" to the U.N. and the ICRC, according to Saudi state-run television.

The Saada attack followed another Saudi-led coalition airstrike Friday at the Red Sea port city of Hodeida hit a telecommunications center key to Yemen’s connection to the internet. Access to the internet has remained "largely down for more than 24 hours" in the country, advocacy group NetBlocks said Saturday.

The Saada air attack, one of the deadliest of the war, was not the first to hit a Houthi-run prison. In September 2019, an airstrike hit a detention center in the southwestern Dhamar province, killing more than 100 people and wounding dozens.

Rights groups have previously documented that the Houthis use civilian detainees as human shields by placing them in detention centers next to military barracks under constant threat of airstrikes.

Friday’s airstrikes in Saada and Hodeida have renewed criticism of the coalition from the United Nations and international aid and rights groups.

Iran on Saturday also condemned recent strikes on rebel-held areas of Yemen, warning they make achieving peace in the war-torn country "more difficult."

"The continuation of the coalition's military attacks on Yemen with the silence and indifference of the international community and the uncontrolled sale of weapons to the aggressors ... has made the path to achieve a just peace in the country even more difficult," Foreign Ministry Spokesperson Saeed Khatibzadeh said in a statement.

Khatibzadeh said there was a lack of "serious determination to advance the political settlement of the Yemeni crisis", warning it will lead to the "destruction of the country and instability in the region."

"The countries that provide the coalition with bombs and weapons of mass destruction are complicit in these crimes and must be held accountable," Khatibzadeh added.

Saudi-led coalition airstrikes have hit schools, hospitals and wedding parties, killing thousands of civilians. The Houthis meanwhile have used child soldiers and indiscriminately laid land mines across the country. They also launched cross-border attacks using ballistic missiles and explosives-laden drones on Saudi Arabia and the UAE.

The coalition continued its airstrikes on Sanaa and elsewhere Saturday, targeting a Houthi-held military facility and an abandoned headquarters of Yemeni state TV in the capital. The coalition said airstrikes also targeted the Houthis in the contested Harib district in Marib.

The UAE-backed Giants Brigades said they shot down three drones carrying explosives launched by the Houthis on government-held areas in Marib and Shabwa provinces.

The rebels, meanwhile, held a funeral procession in Sanaa for a senior military official killed along with family members in a coalition airstrike last week. Hundreds of Houthi supporters attended the military funeral of Gen. Abdalla Kassem al-Junaid, who headed the Air Academy, according to an AP video journalist.

U.S. Secretary of State Antony J. Blinken urged the warring parties to end the escalation of fighting and attacks across Yemen. "We urge all parties to commit to a peaceful, diplomatic solution to ending the conflict. The Yemeni people deserve to live in peace and determine their own future," he wrote on Twitter.

The latest escalation comes almost a year after President Joe Biden’s administration announced an end to U.S. support for the coalition and removed the designation of the Houthis as a terrorist group as part of American efforts to end the grinding war.

The Houthi-claimed attack on the UAE on Monday prompted Biden to say that his administration would consider restoring the status of the Iranian-backed rebels as terrorists.

The Arab League will also hold an emergency meeting at the level of permanent delegates on Sunday to discuss the attack on the UAE. The meeting will be held at the request of the UAE and other Arab countries, Ambassador Ahmed al-Bakr, the Kuwaiti delegate to the Cairo-based league, said in statements cited by the state news agency KUNA.

Al-Bakr, whose country is the current chair of the pan-Arab body, said the meeting will discuss this week's terrorist Houthi attack on Abu Dhabi.

On Friday, the U.N. Security Council unanimously condemned the Houthi attack on the UAE and called for the perpetrators to be brought to justice. But the council's Norwegian presidency also denounced the strikes on Yemen.

In a later statement, the U.N. chief Antonio Guterres "remind(ed) all parties that attacks directed against civilians and civilian infrastructure are prohibited by international humanitarian law."

The latest escalation of fighting was the most intense since the 2018 battle for Hodeida and comes after a year of U.S. and U.N. diplomatic efforts failed to bring the two sides to the negotiating table.

The rebels have repeatedly pushed back against U.N. and U.S. calls to halt the offensive on oil-rich Marib province. The Houthis have been trying for a year to take Marib to complete their control of the northern half of Yemen. That would likely give them an upper hand in any future negotiations.

"The coalition has pulled the stops out to prevent a collapse in Marib and to shift the conflict towards a military equilibrium," said Peter Salisbury, Yemen expert at the International Crisis Group.

The conflict in the Arab world’s poorest country began in 2014, when the Houthis took Sanaa and much of northern Yemen, forcing the government to flee to the south, then into exile in Saudi Arabia. The Saudi-led coalition, backed at the time by the U.S., entered the war months later to try to restore the government to power.

The conflict has since become a regional proxy war that has killed tens of thousands of civilians and fighters. The war also created the world’s worst humanitarian crisis, leaving millions suffering from food and medical care shortages and pushing the country to the brink of famine.