The UN rights chief expressed alarm Tuesday at the situation in Yemen as Arab warplanes pounded the country for a sixth day, warning it appeared about to collapse.

"The situation in Yemen is extremely alarming, with dozens of civilians killed over the past four days," UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein said in a statement.

"The country seems to be on the verge of total collapse."

Zeid's comments came after nearly a week of air strikes by a Saudi-led coalition, which has vowed to continue the attacks until Huthi rebels end their uprising against President Abedrabbo Mansour Hadi, who has fled to Saudi Arabia.

Since Friday, at least 93 civilians have been killed and 364 injured in the violence, the UN human rights office said Tuesday.

"We have reports that the hospitals are really full of dead and injured people," spokeswoman Cecile Pouilly told AFP. "We have heard about lots of dead bodies," she added.

Zeid voiced outrage at the high toll.

"The killing of so many innocent civilians is simply unacceptable," he said.

The UN rights chief said he was particularly shocked by an air strike on Monday against the Al-Mazraq camp for displaced people in northwest Yemen.

The International Organization for Migration said at least 40 people had been killed and 200 wounded in the attack, and medics at a hospital near the camp gave a similar toll.

Zeid's office said its staff had personally verified that at least 19 people had died and at least 35 had been injured, including 11 children.

The camp, which is home to some 4,000 people, was set up by the United Nations in 2009 and recently received at least 300 new families fleeing unrest in Saada, the northern stronghold of the Huthis, the statement said.

Zeid also denounced reported attacks by Huthi-linked fighters on three hospitals in the southern town of Daleh, causing an unknown number of casualties.

"I roundly condemn all attacks on hospitals and other medical facilities, which have a special protected status under international law," he said.

A government official told AFP Monday that the rebel attack on Daleh had killed eight civilians, including two children, when they opened fire using tanks and artillery.

Hundreds more had reportedly fled their homes in Saada, Daleh and elsewhere, it said.

"Private homes, hospitals, education facilities and infrastructure in several locations have been destroyed, making life even more difficult for the people in the war-torn country," Zeid said.

EU 'distressed' by Yemen civilian deaths
Brussels (AFP) March 31, 2015 - The European Union expressed concern Tuesday at civilian deaths in Yemen after days of Saudi-led air strikes against rebel forces including one that killed scores at a displaced persons camp.

"We are extremely concerned about the impact of the fighting in Yemen which has terrible consequences for the population," a spokeswoman for EU foreign policy chief Federica Mogherini said in a statement.

"The news of civilian casualties is distressing."

The 28-nation bloc said it had learned with "strong concern" of Monday's airstrike on the Al-Mazrak camp in Hajja province in which aid workers said at least 40 people had been killed.

"We call on all parties to the conflict to ensure the protection of civilians, that civilian infrastructure is not directly targeted," it said.

A Saudi-led Arab coalition has been pounding Shiite rebel positions in Yemen since early Thursday.

Mogherini said last week that military action was "not a solution" to Yemen's problems and warned of regional risks, calling on regional players to negotiate a peace settlement.