On the morning of September 28, two families gathered in the southwestern Yemeni village of Wahija for the wedding of a young couple.

Dozens of women were inside a large wooden structure owned by the family of the groom, Merssal Mosaibas, helping to prepare for the festivities. A few male relatives and guests, both men and boys, were outside.

At about 9:30am, the familiar roar of Saudi-led coalition jets was heard overhead. Some people fled as the planes approached, fearing an attack, but many women and children remained inside. Bombs started falling shortly after 10am, the first striking near where the men had gathered. The structure, held up by tree branches and covered with a tarp, was obliterated minutes later. Mosaibas was nearby, but survived the attack; his bride, Hanen Makhrama, had not arrived yet from her nearby village.

The women and children inside the structure, however, were killed.

Wedding guest Shadi Taha told VICE News over the phone that the attack turned what had been a scene of joy and celebration into one of horror. Body parts were scattered all over, tree branches flecked with pieces of skin.

"There were only small, small pieces," he recalled. "People were small, small pieces of meat."

The site of the coalition airstrike that allegedly killed dozens of people at a wedding in Wahija, a village on the Red Sea coast in southwestern Yemen. (Photo via Human Rights Watch)

Among the dead were a mother and her five children. The body of an elderly woman who lived nearby was found on her bloodstained mattress. She had been resting when shrapnel tore through her home.

"It cut her into two or three parts," Taha said. "We had to carry her out in a carton."

The jets circled for half an hour, leaving residents fearful to help victims.

"Later, when we did try to rescue them, we could find [only] a single person alive," a local community leader told United Nations investigators as part of their monitoring of abuses in Yemen. The UN's Office for the High Commissioner for Human Rights provided VICE News with his testimony and other witness accounts.

Initial reports put the death toll as high as 130, citing local health officials. Human rights workers and locals later clarified that at least several dozen people died, most likely between 30 and 50 people. Many of the bodies were too badly burned or mangled to identify immediately or at all. Because a large number of the wedding guests came from outside the town and others fled before and after the attack, those who survived did not know how many people were present when the bombs exploded.

Another woman told UN investigators that she called her 21-year-old daughter upon hearing planes nearby, urging her to leave. But the daughter stayed and was killed.

"Once we reached the site of the airstrike, all we could find were body parts," the mother said. "We could not find part of her dress or clothing so that we could identify our daughter."

After more than six months of Saudi-led airstrikes targeting Houthi rebels and their allies in Yemen, incidents like this have become grimly familiar. According to UN figures, more than 2,355 civilians have been killed since the hostilities began in late March.

The Houthis and allied forces loyal to former President Ali Abdullah Saleh have been implicated in the deaths of hundreds of non-combatants, often killed by indiscriminate and retaliatory shelling or mines left behind as the Houthis retreat. But the UN says that airstrikes have killed the majority of civilians. The United States military has assisted this Saudi-led campaign with logistical support and billions of dollars in equipment and weaponry.

The Houthis, who hail from a northern Zaydi Shia community, control Wahija and the area around it. One resident said the groom's uncle was associated with the Houthis, but there was no indication that the wedding in any way amounted to a military target.

Human rights monitors and the UN have heavily criticized the massive civilian toll from such strikes and the US military's supporting role. They have also raised questions about Washington's potential complicity in war crimes and violations of international law. UN Secretary-General Ban Ki-moon has said that the campaign must stop.

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Last week, in its latest condemnation of the Saudi-led coalition and its backers, Amnesty International outlined what it called likely war crimes committed by the coalition in the northeast province of Sadaa, a Houthi stronghold. It called for a suspension of all arms transfers to the coalition by its backers, including the United States and United Kingdom.

Since October 2010, the US has sold Saudi Arabia more than $90 billion in aircraft, defense systems, bombs, missiles, and other weapons. When war broke out in Yemen, it began to expedite shipments. American arms manufacturers have also sold billions of dollars' worth of material to other Gulf coalition members, including the United Arab Emirates and Qatar. Both the Saudis and UAE have purchased controversial cluster munitions — banned by more than 100 countries — that have been used in the current conflict.

Since the airstrikes started on March 25, the US has provided the coalition with vital air-refueling sorties, search-and-rescue support, and help with logistics and intelligence — the centerpiece of which is a Saudi-based "Joint Combined Planning Cell" staffed with American personnel who interact daily with the Saudi military. This support involves what the US military's Central Command (CENTCOM) terms "targeting assistance."

"The Saudi-led coalition is equipped with state-of-the-art weapons and targeting technology, yet airstrikes have caused a tremendous number of civilian casualties," said Claire Talon, Middle East and North Africa director at the International Federation for Human Rights. "It is clear that states providing intelligence and assistance to the coalition, including the US, may be accused of complicity in war crimes."

'The Saudis are using Yemen as an experiment lab for violence, and this will have an extensive impact in the long term.'

But proving that the US has abetted war crimes or violations of international humanitarian law — or even obtaining the information to make a judgment about potential American responsibility — is difficult. From the start, the US has insulated itself from the fallout of a bloody intervention that it has helped sustain. Behind the scenes and in select public statements, American officials have urged the Saudis to be more careful, but there is no indication that the Obama administration has in any way adjusted its assistance in light of the continuing civilian toll.

On October 2, alluding to the Wahija wedding strike, the White House's National Security Council said that the administration was "deeply concerned" about civilian casualties and called on "all sides of the conflict in Yemen to do their utmost to avoid harm to civilians."

"We call for an investigation into these reported civilian casualties and for the findings to be reported publicly," said NSC spokesman Ned Price, though he emphasized that the US "has no role in targeting decisions made by the coalition in Yemen."

But the language used in that statement is potentially misleading according to Sarah Knuckey, director of Columbia University Law School's Human Rights Clinic.

"When I saw the statement, it struck me as carefully crafted but opaque," she said. "When you first read it, it seems to say that the US is not involved in strikes — and that's how some people interpreted it — but reading it as a lawyer the statement is actually quite ambiguous. It leaves open that the US could be providing intelligence, even if it's not 'deciding' on targets."

For more than three months, VICE News has requested comment and information from multiple officials at the White House, CENTCOM, and the Pentagon about the extent of US involvement with the coalition, and what steps the US is taking to prevent civilian casualties.

"There is a clear distinction between logistical and intelligence support, which we have provided, and taking part in targeting decisions, which we do not," said a senior White House official who did not wish to be identified when asked about the NSC's statement. "We have provided logistical and intelligence support in part to facilitate accurate and precise coalition operations in an effort to minimize civilian casualties."

But it is unclear how this support works to minimize casualties, if it does at all. The White House would not clarify what information the US provides to the Saudis in order to avoid such casualties, and referred VICE News to the Pentagon.

"Ultimately, it is the KSA [Kingdom of Saudi Arabia] that makes the final decision on targeting," said Major Roger Cabiness, a Pentagon spokesman. "We will continue to be vocal and adamant on the importance of precise targeting and the importance of thoroughly investigating all credible allegations of civilian casualties."

Watch VICE News' 'Yemen: A Failed State.'

Lieutenant Commander Kyle Rains, a spokesman for CENTCOM, which has authority over all US operations in the Middle East, responded similarly, instructing VICE News to "contact the Saudi government for information on the tracking of civilian casualties." But the Saudi government has provided no reliable data.

Neither the Pentagon nor CENTCOM answered when asked if the US military is in any way reviewing the toll on civilians inflicted by coalition airstrikes that it is supporting, or crafting measures to mitigate such casualties. Other sources in the US government said that measures employed by the military in other conflicts to prevent such casualties, such as civilian harm tracking, have not been explicitly coupled with American assistance for the Gulf coalition.

"I think what we are seeing in Yemen makes clear that the US needs to be deliberate in its efforts on civilian harm mitigation," said a US official with intimate knowledge of American support for the Saudi-led coalition. "To this point, it has not been part of the approach."

The official, who spoke on condition of anonymity due to the program's sensitive nature, added that the view within the Pentagon and among those who are coordinating support for the Saudi intervention in Yemen is that offering superior intelligence and targeting capabilities will decrease civilian casualties.

For their part, the Saudis often deny that airstrikes cited by human rights officials were even carried out by their coalition. With the exception of the longstanding US drone program targeting al Qaeda's Yemen affiliate — which is also believed to have killed dozens of civilians, some at wedding gatherings — the Saudi-led coalition is the only air power operating above Yemen. When asked, the Saudi Embassy in Washington, DC would not say how the Saudi government is investigating civilian casualties or working to prevent them.

In September, UN human rights chief Zeid Ra'ad al Hussein called for an independent international inquiry into possible crimes committed in Yemen over the past year. Soon after, the Netherlands proposed a resolution at the UN's Human Rights Council that would authorize a UN mission to gather evidence. Under intense pressure from the Saudis and other Gulf states, and with little support from the US, the Dutch folded. A Saudi-drafted text affirming UN assistance for the Riyadh-supported government of Yemeni President Abd Rabbu Mansour Hadi was passed instead.

Human rights officials say that the existing inquiry established by Hadi's government, just like Saudi claims that they will investigate their own airstrikes, do not hold up to international standards of impartiality.

"One way to have settled who provided the targeting for the catastrophic attack on the wedding would have been an international inquiry, but sadly the US did not lift a finger to make that happen," said Sarah Leah Whitson, Middle East and North Africa director at Human Rights Watch.

While CENTCOM officials insist that the American assistance program is "primarily an advisory one," experts counter that the coalition would have immense difficulty operating politically and militarily in its absence.

'The number of countries that are capable of aerial refueling is amazingly few. The US remains uniquely equipped to provide logistical support and a wide range of kinds and types of intelligence.'

"Without US in-air refueling, combat search-and-rescue, a steady and expedited flow of weapons and ammunition, and contractor logistical support, the air campaign couldn't happen," said Micah Zenko, a senior fellow at the Council on Foreign Relations who has been closely studying the intervention.

Chis Jenks, a professor of international law at Southern Methodist University and a 20-year veteran of the US armed forces, said that while the US is not officially a member of the Saudi-led coalition, it is difficult to overestimate how essential it is to the campaign.

"The number of countries that are capable of aerial refueling is amazingly few," he said. "Even among our NATO allies, they rely on the US. The US remains uniquely equipped to provide logistical support and a wide range of kinds and types of intelligence, including signals intelligence on radio, cell and other forms of communication, and satellite imagery products."

Jenks, who helped train the Yemeni army during Saleh's presidency, said coalitions like the one operating in Yemen are constructed in a way that protects members and countries like the US, which occupy a sort of grey area.

"The White House may well be able to claim that the US is not making targeting decisions or launching airstrikes, and that it doesn't control the military forces of other countries which are — so as a matter of law, the US is not obligated to conduct an investigation into allegations of civilian casualties," he said. "It seems now that there is a tendency within coalition operations to not acknowledge which countries in the coalition are taking what action. Coalition operations are providing an effective way to deflect media inquiries and concerns about civilian casualties."

The dearth of information on coalition activities and the lack of an impartial investigation into civilian casualties has alarmed human rights monitors.

"If there were to be a proper investigation, first and foremost responsibility would have to be established as to who are the primary perpetrators of any attack," said Donatella Rovera, Amnesty International's senior crisis response advisor. "And then who might have provided assistance of some sort, be it logistical or intelligence or supplying weapons, even if those weapons might have been supplied some time ago."

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On October 7, five days after the White House statement on casualties, coalition jets hit another wedding, this time in Sanaban village in Dhamar governorate. According to witnesses who spoke with UN investigators, one of three brothers who were to be married was killed.

The Saudi-led coalition claims that the Houthis are a proxy for Iran, and accuse Tehran of supporting the rebels. The extent of Iran's backing is disputed, and support from forces loyal to Saleh, armed with his weapons stockpiles — including arms supplied by the US — have played an outsized role in the rebels' advances. Still, in Washington, the fight in Yemen is often considered a proxy war between Iran and Saudi Arabia.

A Yemen-based human rights official said that the US is driven to provide support in order to placate the Saudis after their opposition to the nuclear deal that the US and other world powers reached with Tehran this summer.

"It comes down to the Iran nuclear deal, and this is the price to be paid, the pound of flesh," said the official, who spoke to VICE News on condition of anonymity due to the official's ongoing work in the country. "The Saudis get to do whatever they want to do in Yemen."

Farea al-Muslimi, a visiting scholar and expert on Yemen at the Carnegie Middle East Center, said that the unconditional support that the US, the UK, and other Western countries provide to the coalition has "led the Saudis to be more destructive in their use of force."

"Now the Saudis are using Yemen as an experiment lab for violence, and this will have an extensive impact in the long term," he said.

For the people of Wahija, the geopolitical implications of the war in Yemen are the least of their worries. Jets continue to fly over the town and other villages like it, and civilians continue to live under a daily threat of attack. Residents in the area said recently that they were still finding the remains of friends and neighbors scattered around the town.

Many Wahija residents fled after the September 28 bombing to take shelter elsewhere. One of them, Abdullah Saleh Omar, returned on the afternoon of the bombing to check on his house.

"We found half the body of a woman in my house," he said. "Between the trees all around my house people found body parts — arms and legs."