Yemen conflict: Saudi-led coalition resumes air strikes despite truce
A Saudi-led coalition has resumed air strikes in Yemen, hours after a humanitarian truce came into effect.
The ceasefire started at midnight on Sunday, but was pierced by a strike on rebels after they attacked Aden airport with rockets.
There was further fighting in the south on Monday, as Houthi militias shelled residential areas in the city of Taiz.
The truce, agreed by Saudi Arabia, was originally called to allow aid agencies to access civilians.
At least 1,700 people have been killed in fighting in Yemen and thousands of others are in desperate need of food and medical supplies.
But the Houthis - who control much of the north of the country and the capital, Sanaa - said they hadn't been officially informed of the ceasefire.
At least 11 rebels and five civilians were killed during fighting in Taiz, AFP reports.
Coalition warplanes also mistakenly hit pro-government forces in the southern province of Lahj on Monday, according to security officials, killing at least a dozen loyalist fighters.
Saudi Arabia has yet to comment on the deadly strike.
The Saudi-led coalition has been bombing Houthi militia and forces loyal to former president Ali Abdullah Saleh since 26 March.
On Saturday, it said it would suspend bombardment for five days - but that it reserved the right to respond to "military activity or movement" by Houthi rebels.
The unexpected ceasefire was announced after Yemen's exiled President, Abdrabbuh Mansour Hadi, wrote to Saudi Arabia's King Salman asking for a break, to allow humanitarian supplies to be delivered.
More than 80% of Yemen's 25 million people now need some form of aid, the United Nations says.
Johannes van der Klaauw, the UN humanitarian co-ordinator for Yemen, made an urgent appeal for a pause in the fighting.
"I repeat my plea to all parties of the conflict to put an end to the attacks on civilians and to end the destruction of critical infrastructure, vital for supplying essential goods and services to the civilian population," he said in a statement.
Key players in the war
Houthis - The Zaidi Shia Muslim rebels from the north overran Sanaa last year and then expanded their control. They want to replace Mr Hadi, whose government they say is corrupt. The US alleges Iran is providing military assistance to the rebels.
Ali Abdullah Saleh - Military units loyal to the former president - forced to hand over power in 2011 after mass protests - are fighting alongside the Houthis.
Abdrabbuh Mansour Hadi - The president fled abroad in March as the rebels advanced on Aden, where he had taken refuge in February. Loyal soldiers, Sunni Muslim tribesmen and Southern separatists have formed militia to fight the rebels.
Saudi-led coalition - A US-backed coalition of nine, mostly Sunni Arab states says it is seeking to "defend the legitimate government" of Mr Hadi.
Al-Qaeda in the Arabian Peninsula - AQAP opposes both the Houthis and President Hadi. A rival affiliate of Islamic State has also recently emerged.