Cease-fire between Saudi-led coalition, Houthi rebels begins in Yemen

With cargo ships poised to launch a desperately needed aid operation in embattled Yemen, a five-day humanitarian cease-fire began Tuesday night, just hours after Saudi-led coalition warplanes struck against Houthi rebels and their allies.

It wasn't immediately clear if the two sides were honoring the cease-fire, which began at 11 p.m. (2000 GMT, 4 p.m. EDT), but only hours before it was to go into effect, Saudi strikes had pounded the rebel-held Yemeni capital Sanaa.

Among the targets hit was a rocket base — a raid that killed as many as 90 people and wounding 300, a local official was quoted as telling the local Saba news agency. If confirmed, the death toll would be among the highest in a single bombing incident throughout the Yemen conflict.

Residents in the capital also said there were three airstrikes on a base for army contingents aligned with Houthi fighters in the north of Sanaa on Tuesday, sending up a column of smoke.

The bombardments came as the new United Nations envoy to the country arrived in Sanaa ahead of a fresh push to jumpstart stalled political talks among Yemen's civil war factions.

"We are convinced there is no solution to Yemen's problem except through a dialogue, which must be Yemeni," the envoy, Mauritanian diplomat Ismail Ould Cheikh Ahmed, was quoted as saying by Saba news agency.

Seeking to restore exiled President Abd-Rabbu Mansour Hadi, an alliance of Gulf Arab nations has since March 26 been bombing Houthi rebels and allied army units that control much of Yemen.

Backed by Washington, Saudi Arabia worries that the Shia Muslim Houthis are a proxy for what they see as moves by arch-rival Iran to expand its sway in the region. But Tehran has consistently denied providing any direct military support to the Houthis.

The cease-fire on Tuesday was set to take effect at 11 p.m. (04:00 p.m. EDT) to allow the shipment of food and medicine to the blockaded country, which aid groups warn faces a humanitarian catastrophe.

Iran has said it will send a cargo ship full of aid to the Yemeni port of Hodaida, held by Houths. Iranian warships will escort the vessel, a naval commander was quoted as saying by state news agency IRNA.

"The 34th fleet, which is currently in the Gulf of Aden, has special responsibility to protect the Iranian humanitarian aid ship," Admiral Hossein Azad said, referring to a destroyer and support vessel in international waters off Yemen.

Saudi Foreign Minister Adel al-Jubeir was quoted as saying on Monday that the truce in Yemen may be extended if "[aid deliveries] succeeded and if the Houthis and their allies don't engage in hostile activities.”

Adrian Edwards, a spokesman for U.N. refugee agency UNHCR, said planes were poised to take off from Dubai in the United Arab Emirates bearing 300 tons of sleeping mats, blankets and tent material.

"The UNHCR is making final preparations for a huge airlift of humanitarian aid into Yemen's Sanaa, to take place over the next days if today's proposed ceasefire comes into effect and holds," he told a briefing in Geneva.

As the cease-fire neared, witnesses said the Saudi-led alliance bombed Houthi positions in the southern port of Aden, where local armed groups were still fighting the rebels.

Locals said four Aden residents were killed in Houthi shelling, while four anti-Houthi militiamen operating a tank were killed in an Arab air strike – one of the first reported incidents of friendly fire since the campaign began.

On Monday, the Houthis and Saudi forces exchanged heavy artillery fire along the two countries' rugged desert border.

Al Jazeera and wire services