The death toll from a suspected air strike on a wedding party in Yemen on Monday has risen to at least 130, the United Nations and local medics say.
Missiles reportedly hit two tents in a village near the Red Sea port of Mocha, where a man linked to the Houthi rebel movement was celebrating his marriage.
But the Saudi-led coalition that has been bombing the rebels for six months denied responsibility for the attack.
The UN condemned "the disregard shown by all sides for human life" in Yemen.
Secretary-General Ban Ki-moon stressed that there was no military solution to the conflict and its continuation would only bring more human suffering and destruction.
Some 5,000 people, including 2,355 civilians, have been killed in air strikes and fighting on the ground since 26 March, when Houthi fighters and allied army units forced Yemen's internationally recognised president to flee the country.
Last week, Abdrabbuh Mansour Hadi returned to the southern port city of Aden, where his government has set up a temporary base as southern militiamen and coalition forces press northwards towards the rebel-held capital, Sanaa.
Residents of the village of Wahijah said that in Monday's attack, missiles fired by coalition warplanes tore into two tents at the wedding reception.
Yemeni security sources confirmed to the Associated Press that there had been an air strike and a senior government official said it had been "a mistake".
But a coalition spokesman vehemently denied it was behind the attack. A spokesman said: "There have been no air operations by the coalition in that area for three days. This is totally false news."
Initial reports said at least 40 people were killed in the incident, many of them women and children.
But on Tuesday morning, the UN High Commissioner for Human Rights (OHCHR) said 130 or more people were now reported to have died.
A medical source at a hospital in Maqbana, where the casualties were taken, also told the Reuters news agency that the death toll had risen to 131.
"If the numbers are as high as suggested, this may be the single deadliest incident since the start of the conflict," OHCHR spokesman Rupert Colville said.
Mr Colville said almost two-thirds of the civilian deaths reported in Yemen over the past 12 months had allegedly been caused by coalition air strikes.
The UN has also criticised the coalition's naval blockade of Yemen's seaports, which it says has greatly exacerbated the "extremely dire" humanitarian situation.
Some 21 million people, or 80% of the population, now require some form of humanitarian assistance and almost 1.5 million people are internally displaced.