Aden - Fierce gun battles erupted overnight between Yemeni rebels and pro-government forces along the border with Saudi Arabia despite a three-day ceasefire due to end late on Saturday, military officials said.
Warplanes from the Saudi-led coalition fighting in support of President Abedrabbo Mansour Hadi also bombed suspected Huthi rebel missile launchers east of the capital Sanaa late on Friday, a military official said.
The air raids came after Patriot missiles shot down two rebel missiles on Thursday over Marib, east of the rebel-held capital.
UN special envoy Ismail Ould Cheikh Ahmed said on Friday the ceasefire was "fragile but largely holding," urging all parties "to show restraint, avoid further escalation, and strictly adhere to the 72-hour ceasefire."
The truce took effect just before midnight on Wednesday to allow aid deliveries in Yemen, where the war has killed thousands and left millions homeless and hungry.
Government forces
The UN envoy is liaising with the parties in an attempt to extend the ceasefire in order "to create a conducive environment for a long-lasting peace" in Yemen, he said in a statement.
A senior rebel, Hassan al-Sharafi, was killed in border clashes on Friday night in the northern province of Saada, the fiefdom of the Iran-backed Huthis, military officials said.
The rebels seized two hills in the Alb border area from government forces who had previously advanced from Saudi Arabia, a military official said.
It is the sixth ceasefire attempt since the Saudi-led coalition intervened in March last year to support Hadi's government after Huthis overran much of the impoverished country.
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.