Hundreds of people demonstrated in Yemen's rebel-held capital on Tuesday against what they described as the United Nations' "complicity" in the country's deadly 19-month-old war, witnesses said.

The protesters gathered outside a Sanaa hotel where UN envoy Ismail Ould Cheikh Ahmed was staying as he tried to convince the warring parties to accept a ceasefire and resume peace talks.

"Leave, leave Yemen," the demonstrators chanted, addressing the UN envoy whom they accused of "sympathising with Al-Saud", the Saudi ruling family.

Riyadh is leading a military coalition that has been battling the pro-Iran Houthi rebels since March 2015 in support of Yemen's internationally recognised government.

"The UN and the Security Council are complicit in the killing of Yemenis," read one of the banners at the Sanaa demonstration.

Some of the protesters wore shirts showing pictures of the victims of an October 8 coalition air raid on a funeral ceremony in Sanaa that killed 140 people and wounded 525.

The strike prompted severe criticism of the coalition, which has logistical support from the United States.

"Yemenis are massacred and we hold the UN responsible for the actions of Saudi Arabia, America, and Israel," shouted the protesters, who were protected by armed men blocking access to the area.

The rally, which was held in response to calls by the rebels, ended as the UN envoy was to leave the hotel for Sanaa airport, witnesses said.

A statement published by rebel-controlled media said the protesters "condemn the UN envoy's intentional obstruction of the talks" and his "silence on the crimes and massacres committed by the Saudi aggressors" against Yemenis.

A 72-hour ceasefire to allow aid deliveries officially ended at midnight Saturday as the two sides traded accusations of violations.

A call by Ould Cheikh Ahmed to renew the truce for three days was ignored by the warring parties as the coalition stepped up its air strikes and clashes raged on the ground.

Peace talks held in Kuwait ended in deadlock in August.

Nearly 6,900 people have been killed in the conflict, more than half of them civilians, while an additional three million are displaced and millions more need food aid.