The Red Cross and UN flew medical aid into Yemen's capital today after southern city Aden was battered by the heaviest night yet of Saudi-led air strikes targeting Shiite rebels.
The United Nations also called for an immediate "humanitarian pause" of at least a few hours each day, saying aid was desperately needed in the conflict-ravaged country.
The International Committee of the Red Cross said it dispatched an aircraft to Sanaa, its first aid shipment since the international campaign against Shiite rebels began last month.
"This is the first ICRC plane to have landed in Sanaa. It is loaded with 16 tonnes of medical aid," said Marie Claire Feghali, Red Cross spokeswoman in Yemen.
Residents and officials in Aden said the city was pounded overnight after Huthi Shiite rebels and renegade army soldiers loyal to former president Ali Abdullah Saleh arrived at the city's northern entrance.
"The raids began at around 10:00 pm (1900 GMT) yesterday and were the most violent since the start of 'Operation Decisive Storm'," a resident told AFP.
More than two weeks of heavy bombardment by the Saudi-led alliance against opponents of exiled Yemeni President Abedrabbo Mansour Hadi and fighting between rival militias prompted the UN call for a freeze in the violence.
UN humanitarian coordinator in Yemen, Johannes Van Der Klaauw, told reporters in Geneva "immediate humanitarian pause in this conflict" was desperately needed.
He insisted that aid that got through was far from enough.
In the most direct American criticism yet of Tehran's backing for the rebels, Secretary of State John Kerry said yesterday that the United States would not accept foreign interference in Yemen.
"There have been -- there are, obviously -- flights coming from Iran. Every single week there are flights from Iran and we've traced it and know this," he told PBS television.
Iran's leader Ayatollah Ali Khamenei has warned the campaign against the Huthis must end.
"This move is not acceptable in the region and I would warn that they must stop these criminal acts in Yemen," he said on his website.
Today, Pakistan's parliament rejected calls to join the anti-Huthi coalition, turning down longstanding ally Riyadh's request for troops, ships and warplanes.
"Parliament of Pakistan... Underscores the need for continued efforts by the government of Pakistan to find a peaceful resolution of the crisis," it said.
