The raid came after the Saudi-led coalition fighting on the side of Yemen's internationally recognised government against the Huthis bombarded the vital port of Hodeida overnight, triggering a nationwide internet blackout.

The Iran-backed insurgents released grisly video footage of what they said was the aftermath of the attack on the prison in Saada showing bombed-out buildings with rescue workers lifting bodies from rubble and mangled corpses nearby.

"There was a targeting of a detention centre in Saada and currently ICRC teams are inspecting the location to verify the numbers of dead and injured," Basheer Omar, spokesperson for the International Committee of the Red Cross in Yemen, told AFP.

The Saudi-led coalition did not claim the attack on Saada, the Huthis' heartland.

Separately, a coalition air strike hit a telecommunications hub in the port city of Hodeida. Yemen subsequently suffered a nationwide internet blackout, according to a web monitor.

The escalation comes after the Huthis hijacked a United Arab Emirates-flagged ship in the Red Sea, prompting a warning from the coalition, that also includes the UAE, that it would target rebel-held ports.

Yemen's civil war began in 2014 when the Huthis seized the capital Sanaa, prompting Saudi-led forces to intervene to prop up the government the following year.

The Saudi-led coalition said they targeted overnight a "hub for piracy and organised crime" in Hodeida, whose port is a lifeline for the embattled country.

The Huthis said people had been killed in the Hodeida raid, but their statement could not immediately be confirmed. An AFP correspondent in Hodeida described a large-scale attack.

Global internet watchdog NetBlocks reported a "nation-scale collapse of internet connectivity" after the bombardment. AFP correspondents in Hodeida and Sanaa confirmed the outage.

Saudi Arabia's state news agency said the coalition carried out "precision air strikes... to destroy the capabilities of the Huthi militia in Hodeida".

- Regional tensions soaring -

On Monday, the rebels claimed a drone-and-missile attack that struck oil facilities and the airport in the UAE capital Abu Dhabi, killing three people and wounding six others.

The attack -- the first deadly assault acknowledged by the UAE inside its borders and claimed by the Huthis insurgents -- opened up a new front in Yemen's war and sent regional tensions soaring.

In retaliation, the coalition carried out air strikes against rebel-held Sanaa that killed 14 people.

Earlier this month, the Huthis hijacked the UAE-flagged Rwabee in the Red Sea, charging that it was carrying military equipment -- a claim disputed by the coalition and the UAE.

The ship's 11 international crew are being held captive.

The regional escalation follows intense clashes in Yemen, including advances by the UAE-trained Giants Brigade, who drove the rebels out of Shabwa province.

That defeat dealt a blow to the Huthis' months-long campaign to capture neighbouring Marib, the government's last stronghold in the north.

Yemen's foreign minister Ahmed Bin Mubarak said on Friday that he had held a "constructive meeting" with US envoy Tim Lenderking and charge d'affaires Cathy Westley.

"We discussed the recent political, economical and military developments."

"I stressed that international community shouldn't allow a rogue group to tamper with (the) security of the region," he added, referring to the Huthi rebels.

Yemen's civil war has been a catastrophe for millions of its citizens who have fled their homes, with many on the brink of famine in what the UN calls the world's worst humanitarian crisis.

The UN has estimated the war killed 377,000 people by the end of 2021, both directly and indirectly through hunger and disease.

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