A UN envoy arrived in Yemen for talks Tuesday ahead of a planned five-day humanitarian ceasefire, with dozens reported dead in Saudi-led bombing of an arms depot in the capital.

The truce, proposed by Riyadh and due to take effect at 11:00 pm (2000 GMT), aims to allow deliveries of desperately needed relief supplies, although aid groups have already warned that five days is insufficient.

Explosions at an arms depot hit by several coalition strikes since Monday left at least 69 people dead and 250 others wounded in Sanaa, most of them civilians, a medical official said.

The blasts at a military base at Mount Noqum, in the eastern outskirts of Yemen's rebel-held capital, lasted until midday on Tuesday after coalition strikes sent debris crashing into a residential area at the foot of the mountain.

The depot was bombed again on Tuesday, an AFP correspondent said.

Quiet returned to the capital as the newly appointed UN envoy to Yemen, Ismail Ould Cheikh Ahmed, landed in Sanaa after touring Gulf members of the Saudi-led coalition.

"We are convinced that dialogue is the only way to solve the Yemeni problem," the rebel-controlled Saba news agency quoted him as saying.

The Mauritanian diplomat was appointed late last month following the resignation of his predecessor Jamal Benomar who lost support from Gulf states.

Tensions between Sunni-dominated Saudi Arabia and Shiite Iran have soared following the launch of the aerial campaign on March 26

Riyadh has repeatedly accused Iran of arming and funding anti-government Huthi rebels, which Tehran denies.

The Huthis have promised to respond "positively" to the planned truce and allied troops loyal to ousted president Ali Abdullah Saleh have accepted the proposed ceasefire.

- More than 1,500 dead -

The truce would be the first since the Riyadh-led alliance launched an air war aimed at restoring the crumbling authority of exiled President Abedrabbo Mansour Hadi.
The planned ceasefire has strong backing from Washington, which has said it could be extended.

The United Nations has expressed deep concern about the civilian death toll from the Saudi-led bombing campaign as well as the humanitarian impact of an air and sea blockade imposed by the coalition on Yemen.

The UN says more than 1,500 people have died in the conflict since late March.

The Huthis, who hail from Yemen's mountainous north near the border with Saudi Arabia, overran Sanaa in September and extended their control to other regions.

Hadi fled to Riyadh as the rebels closed in on his refuge in the main southern city of Aden, where clashes between his opponents and supporters have shown no sign of relenting.

Six people were killed and 53 others were wounded on Monday in fighting in the port city, Aden health authority chief Al-Khader Laswar said. Civilians were among the casualties.

Clashes also raged in the southern provinces of Abyan, Shabwa, and Daleh, as well as in Baida, Jawf, and Marib farther north, residents said.

Coalition air strikes continued through Tuesday on the Huthi stronghold province of Saada as well as in third city Taez, also the scene of deadly clashes, according to residents.

- 'Catastrophic' humanitarian situation -

The Red Cross spokesman in Sanaa, Adnan Hizam, said a humanitarian truce of more than five days was needed.

"We hope the truce would last longer, and become permanent. And we hope all sides respect it," he told AFP, lamenting a "catastrophic" humanitarian situation.

New York-based Human Rights Watch warned that the Huthis had intensified recruitment of children in violation of international law.

Commanders of the rebels and other groups "should stop using children or risk prosecution for war crimes," the rights group said.

HRW said Islamist and tribal militias as well as Al-Qaeda were also recruiting children.

Al-Qaeda has exploited the growing turmoil in Yemen to consolidate its grip on the southeastern province of Hadramawt.

A provincial commander was among four militants killed in an apparent US drone attack in Hadramawt on Monday, an official said.

Maamoun Hatem headed Al-Qaeda's forces in the central province of Ibb, the official said.

A spokesman for the Saudi-led coalition on Tuesday denied rebel claims that they had shot down a Moroccan F-16 fighter jet, which crashed Monday in Yemen.

"We are definitely sure it wasn't shot down," Brigadier General Ahmed al-Assiri told AFP.

Source: AFP