The airstrikes hit workers' housing for a power plant in Mokha, flattening some of the buildings to the ground, the officials said. A fire erupted in the area, charring many of the corpses, including children, women and elderly people.
Wahib Mohammed, an eyewitness and area resident, said some of the bodies were torn apart by the force of the blast and buried in a mass grave on Saturday. Some of the strikes also hit nearby livestock pens, he said. Human and animal blood pooled on the ground of the surrounding area.
The deadly strike highlights growing concerns that the Saudi-led coalition's airstrikes are increasingly killing civilians as they continue to target Shiite rebels known as Houthis.
"It just shows what is the trend now of the airstrikes from the coalition," said Hassan Boucenine of the Geneva-based Doctors Without Borders. "Now, it's a house, it's a market, it's anything."
He added that many of the workers had families visiting for the Eid al-Fitr holiday at the end of the holy month of Ramadan. Mokha, populated largely by fisherman, had a reputation as one of the safest places in the country embroiled in war, said Boucenine.
Saudi officials could not be reached for comment, and the government's official media did not issue a statement about the deadly strike. Over the course of the war, rights groups like Human Rights Watch and Amnesty International have expressed concern that the Saudi-led coalition is violating laws of war and not doing enough to prevent or minimize civilian casualties.
It is not clear why the workers' housing was hit. Yemeni security officials said the closest Houthi outpost to Friday evening's strike is at least 5 kilometers (3 miles) away. Four airstrikes hit the residence after Saudi-led coalition planes launched dozens of missiles on positions of Shiite Houthi rebels and their allies in the surrounding area. The strikes in the area continued Saturday as dozens of families fled, security officials and eyewitnesses said.
A military official said the coalition had been given incorrect coordinates. He denied that the coordinates had come from anyone in the district and said he called the coalition to inform them of the high number of civilian casualties.
All officials spoke on condition of anonymity because they were not authorized to speak to reporters.
Boucenine, of Doctors Without Borders, said the hospital in Mokha had closed weeks prior due to a lack of medical supplies and staff. Some of the injured died en route to the hospital in the city of Hodeida, 180 kilometers (112 miles) north. The provincial capital of Taiz was inaccessible due to ongoing fighting. Boucenine said the hospital confirmed 44 fatalities, though he expected the actual toll was significantly higher.
Deif Allah al-Shamy, a Houthi leader, called Friday's strike "an ugly crime and a flagrant violation of human rights."
Houthi rebels have also been criticized by rights groups for causing civilian casualties. Houthis and their allies randomly shelled a town earlier this week outside of Aden after losing control of some the port city's neighborhoods, killing nearly 100 people, Doctors Without Borders said.
Since March 26, at least 1,693 civilians have been killed in the Yemen fighting, with 3,829 wounded, the U.N. said earlier this week. It says civilians have been killed by mortar fire and ground fighting though "the majority of the casualties are reported to have been caused by air strikes."
The fighting in Yemen pits the Houthis and troops loyal to former President Ali Abdullah Saleh against southern separatists, local and tribal militias, Sunni Islamic militants and loyalists of exiled President Abed Rabbo Mansour Hadi, who is now in Saudi Arabia.
The U.N. human rights office said in a statement this week that "since 17 June, there has been further destruction of civilian infrastructure, with at least 36 buildings, including hospitals, schools, court houses, power generation facilities, and communications institutions partially or totally damaged."
Less than a day after the deadly strike, the Saudi-led coalition announced it will start a five-day humanitarian pause in Yemen on Sunday just before midnight.
The statement, carried on Saudi state media Saturday, said the unexpected pause came as a result of a request by Hadi to Saudi's King Salman.
It said the coalition will cease military operations, but that it will respond should Houthi rebels or their allies conduct any military actions or movements.
The truce is intended to give pause to months of punishing fighting in the war-torn impoverished Gulf nation and allow for the dispersing of much-needed humanitarian aid.
The previous humanitarian pause, which was announced earlier this month and was expected to last until the end of the holy month of Ramadan, never truly went into effect as both sides blamed each other and civilian deaths continue