A suspected Saudi-led coalition air strike has killed at least 131 civilians, including many women and children, at a wedding in Yemen, medical officials said on Tuesday.

UN Secretary-General Ban Ki-moon condemned Monday's air raid, saying intentional attacks on civilians were considered a "serious violation of international humanitarian law".

Residents said the Arab coalition, which launched an air war on the Houthi rebels in late March, was behind the attack on the wedding hall near the Red Sea city of Mokha.

The death toll rose to 131 people after "more bodies were taken overnight to hospital and many of the wounded succumbed to their injuries," a local health official told AFP requesting anonymity.

Previously the toll had been at least 40 dead and dozens wounded.

A doctor at Mokha's Al-Reefi Hospital, Mayaz al-Hamadi, confirmed that 131 bodies, including women and children, had been brought in.

"Many bodies are laid on the floor because the hospital does not have the means" to accommodate the large number of fatalities, he said.

The United Nations said it was trying to verify the death toll.

"If the numbers are as high as suggested, this may be the single deadliest incident since the start of the conflict," UN rights agency spokesman Rupert Colville told reporters in Geneva.

Colville said that more civilians were being killed in the fighting in Yemen amid "an increasing number of air strikes targeting bridges and highways".

According to new UN numbers, 151 civilians were killed, including 26 children and 10 women, in the conflict from September 11-24.

A total of 2,355 civilians have been killed in the war since late March, and 4,862 more wounded, Colville said.

Ban urged all rival sides in Yemen "to immediately cease all military activities and resolve all differences through peaceful negotiations".