Between 15 and 40 civilians including two to five children and one to three women died, and up to 15 more were injured, in airstrikes on multiple locations in Al Mayadeen. Local sources were initially conflicted as to whether this was the work of the Coalition, Iraqi warplanes or Russia.

However, in April 2018 the Coalition claimed responsibility for the event:  “It was assessed that during a strike on an ISIS media center and headquarters 15 civilians were unintentionally killed.”

In an interview with ITV News in summer 2019, British ISIS fighter Alexanda Kotey claimed that up to 40 people died when a single apartment block [presumably the al-Dahmoush building, see below] was bombed that day – including a notorious British ISIS supporter Sally Jones, known as the ‘White Widow’, and her 12-year-old son Jojo.

Many sources, including Euphrates Post, the Syrian Network for Human Rights and the Smart News Network, initially reported the death of four non-combatants on May 25th. Other sources, however, put the death toll higher, with the Syrian Observatory for Human Rights reporting that up to 35 civilians died, including many family members of IS.

According to the Syrian Observatory, “Reliable sources confirmed to the Syrian Observatory for Human Rights that the strikes on the Dahmoush building have killed 26 other people at least, most of them are from the families of the organization’s members, others were injured and went missing due to these airstrikes. The Syrian Observatory learned that those who were killed, injured and missing belonged to 7 families of members of the ‘Islamic State’ organization”.

On May 30th Euphrates Post also reported “The death of the mother of Saddam, the wife of Hussein al-Hamad al-Arrouk, who was injured by the raids that targeted the city of Al-Mayadeen a few days ago. She joins her husband, her sons, her daughter and her grandson.”

The Observatory documented a number of strikes by Coalition jets: “At 7:25 pm two warplanes accompanied by two drones hovered in the sky of Al-Mayadin city, coinciding with citizens’ entry to the city’s mosques. Both warplanes carried out 4 strikes using 4 consecutive rockets, the first two rockets targeted the 4-storey al-Dahmoush building, which housed family members of the ‘Islamic State’ organization of Syrian and Moroccan nationalities. It was destroyed completely, and the raid killed a man and 2 women and a baby from Al-Mayadin. A second raid targeted the market of the city, which killed a woman, her 2 children and 2 other children. The number of Syrian people who were killed has become 9, including 5 children and 3 citizen women.”

Arabic.rt also put the death toll at 35 and blamed the Coalition.

However, Zamanalwsl pointed towards Iraqi warplanes.

Two other sources – Alaraby and @abojannarawi201 said that Russia was responsible.

According to Alaraby, Russian warplanes carried out three strikes, and “one of the raids targeted the market of the Office of the vicar in the city centre, and civilian homes resulted in the deaths and injuries.”

The Syrian Observatory for Human Rights later reported: “The Syrian Observatory for Human Rights received information from reliable sources about the presence of Ryan Meshaal in al-Dahmoush building 3 hours before it was targeted by the International Coalition; at 7:25 in the evening of Thursday the 25th of May 2017, while the Syrian Observatory can’t confirm whether Ryan Meshaal [one of the founders of IS media agency A’amaq] is among those who were killed by the airstrikes that targeted the building and killed 26 persons of the organization’s families, also the airstrikes caused injuries and some people gone missing, where the Syrian Observatory learned that those who were killed, injured and lost belong to 7 families of the Islamic State organization’s members.”

The Coalition provided Airwars with the location of this incident, accurate to within a 100-metre box.

The local time of the incident is unknown.

At least 22 civilians were killed in a Coalition airstrike on the village of al Ghandourra. According to Syria Newsdesk, the noon strikes hit the main market and the elementary school in the town, which was occupied by so-called ISIL.

The US later admitted to inadvertently killing 15 civilians in the incident, claiming that “the munition struck the vehicle after it slowed in a populated area after the munition was released.”

Extremely graphic footage later released by ISIL’s media wing showed much of the market destroyed, with significant civilian casualties. One unnamed eyewitness states: “Today the crusader coalition planes bombed this market, a market full of civilians, so that pieces of bodies were flying around, men, women and children. There are bodies that have turned to charcoal that can’t be identified, and others are in pieces that their families can’t identify them. Is this place a place of the mujahedin? We ask God almighty to destroy America and all those who support it, we ask God to destroy the coalition and all its allies and all those who are fighting Muslims, all those who are aggressing against Muslims. Where are you Muslim ummah where are you?”

According to the Syrian Observatory, 28 civilians “were killed when warplanes of the international coalition committed a massacre in the town of al-Ghandour in the northwestern countryside of Manbij city east of Aleppo province. The town is more than 23 kilometres away from Manbij city, and the death toll is expected to rise because there are some people in a critical situation. Also, SOHR received information that 13 other people were killed in the same bombing, but they were not identified yet, and it is unknown whether they were civilian citizens or members from the ‘Islamic State’.“

The Pentagon announced later that day it was conducting an investigation into al Ghandourra: “U.S. Central Command initiated an assessment following internal operational reporting that a strike today near Manbij, Syria may have resulted in civilian casualties. We can confirm the Coalition conducted airstrikes in the area in the last 24 hours.” A senior US military official told Airwars that the Coalition’s internal monitoring had already raised concerns relating to the al Ghandourra strike – and that the decision to proceed almost immediately to an investigation represented a more pro-active approach to civilian casualty allegations.

An Amnesty case study published in October 2016 used satellite and photograph analysis to determine the likelihood of civilians having been killed: “The strikes reportedly hit the public market, as shown in a video clip which Amnesty International was able to geolocate in al-Ghandoura’s central main street and other images of the immediate aftermath of the attack in which dead bodies and significant destruction is clearly visible. One child victim shown in several on-line images of the attack’s aftermath is also clearly visible at the start of the video clip. Amnesty International was unable to find any of the images on-line before the date of the incident,” the NGO noted. “Amnesty International is concerned that the loss of civilian life in the strike resulted from a failure by the Coalition forces to take necessary precautions and the attack may have been disproportionate or otherwise indiscriminate.”

The Coalition conceded that it had killed 15 civilians in a statement issued on December 1st 2016: “Near Arghanndorh, Syria: During a strike on a moving ISIL vehicle, 15 civilians were inadvertently killed when the munition struck the vehicle after it slowed in a populated area after the munition was released.”

The Syrian Network eventually concluded that 22 civilians had died in the attack. It quoted local eyewitness Mr. Safi Al Sayed: “I saw two warplanes for the international coalition forces soaring in the sky. They were supporting the Kurdish forces in their clashes with ISIS near our town. The warplanes fired a missile that targeted shops near the town mosque. In just moments, the shops were reduced to ruins and everyone was inside were turned into burned dead bodies. I smelled the burned dead bodies. It was a tough thing to see.”

In July 2019 the Coalition provided Airwars with the location of this incident, accurate to within a 100 metre box.

The local time of the incident is unknown.