Aid groups and rebels who control the Yemeni capital appealed on Wednesday to a Saudi-led coalition backing the government to allow the reopening of its airport now closed for a year.

The coalition of Arab states forced the closure of Sanaa airport to all but very limited UN flights in August last year saying it was necessary to prevent arms smuggling.

But aid groups have warned that the closure is hampering the delivery of desperately needed supplies which now have to go through the Red Sea port of Hodeida.

"The sick can no longer travel abroad for treatment and medicines can no longer be brought in," the rebels' transport minister Zeid al-Chami told reporters.

He appealed to the international community to put pressure on the Arab coalition to relent.

The Norwegian Refugee Council (NRC) said the coalition's blockade of the airport was causing more deaths than its air strikes on the rebels.

"10,000 Yemenis have now died from health conditions for which they were seeking medical treatment abroad," the aid agency said, citing figures from the rebels' health ministry.

"The number exceeds the alarming death toll of close to 9,000 people killed in violent attacks."

NRC country director Mutasim Hamdan said it was vital that the airport reopen.

"It is critical that all channels of domestic and international air movement are reopened so Yemenis can get help, and help can get to Yemenis," he said.