In a new US atrocity in Syria, American warplanes on Thursday bombed a market in the ISIS-controlled village of al-Ghandour near the northern city of Manbij, killing at least 28 civilians, including seven children. According to a report by one monitoring organization, an additional 13 people, possibly ISIS fighters, were killed in the airstrike.

The latest mass killing occurred in the same region where, nine days before, the US military bombed a group of houses in the village of Tokhar, where nearly 200 people had gathered to seek refuge from fierce fighting between US-backed forces and ISIS militants near Manbij. Virtually all those inside the houses were killed or injured, with the reported civilian death toll varying from a low of 56 to a high of more than 200.

That massacre was the single most deadly bombing attack on Syrian civilians inflicted by any warring party since the US launched its war to overthrow the Russian- and Iranian-allied regime of Syrian President Bashar al-Assad five years ago. Over 400,000 people have been killed and millions of civilians have been displaced and turned into refugees as a result of the US-instigated civil war.

Thursday's deadly airstrike in al-Ghandour came one day after the US military announced it had initiated a formal inquiry into the July 19 bombing of Tokhar. Such inquiries are cynical whitewashes. It takes on average seven months for the release of a redacted version of the findings, which inevitably minimize the scale of the war crime and attribute it to inadvertent errors.

Following the attack on al-Ghandour, the US Central Command issued its standard, pro forma denial: “We take all measures during the targeting process to avoid or minimize civilian casualties or collateral damage and to comply with the principles of the law of armed conflict.”

The contempt of the US government for the Syrian people and indifference to the mass suffering it inflicts are summed up by the absurdly low figures it gives on civilian casualties from American airstrikes. The US Central Command this week released the results of its investigations into civilian casualties in Iraq and Syria over the past year and concluded that only 14 civilians had been killed in six separate US attacks. Washington claims its bombs have caused a total of 55 civilian deaths since the US-led air war against ISIS was launched two years ago.

But groups that maintain a tally of the civilian toll, such as Amnesty International and Airwars, say the real figure is at least 10 times the US number, and could be far higher. Amnesty’s researcher for the region, Neil Sammonds, puts civilian deaths from attacks by the US-led coalition at over 1,500 across Iraq and Syria.

Following Thursday’s attack on Tokhar, Sammonds told the Guardian newspaper, “Levels of civilian killings from the coalition are so high now, we are edging towards the 1,000 figures, and they don’t disclose it, they are covering it up…

“They dismiss evidence pointing to civilian casualties if it hasn’t been captured from the sky by their own operatives, so even if there are photographs of scores and scores of dead bodies, with names, it’s still discounted.”

The Syrian Network for Human Rights, which is part of the anti-Assad opposition, says coalition strikes have killed more than 400 civilians in Syria alone.

In 2015, a London-based group of journalists released a report saying that in the coalition’s first 12 months of airstrikes in Syria and Iraq, it killed 459 civilians in 57 incidents.

Even US-backed opposition groups in Syria denounced Thursday’s attack as a “massacre.” The Syrian National Coalition (SNC) in a statement posted on Twitter declared, “The international coalition committed a new massacre in the Manbij countryside when it bombed the area of Al-Ghandora yesterday, killing dozens of people, among them children.”

The London-based Syrian Observatory for Human Rights said the civilians in Tokhar “were killed when the 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… and the death toll is expected to rise because there are some people in critical situation.”

The US claim that war crimes such as the July 19 bombing of Tokhar and the July 28 attack on al-Ghandour are merely accidents is a lie. Following the Tokhar airstrikes, the SNC sent a letter to the foreign ministers of the coalition’s member nations demanding immediate suspension of the coalition’s military operations to allow for a thorough investigation of that attack. The US flatly refused.

Washington considers winning control of Manbij, a strategic transit point in the governorate of Aleppo between Turkey and the ISIS “capital” of Raqqa, to be critical to the campaign against ISIS. It is backing Kurdish-dominated forces fighting ISIS in the region.

More importantly, the US is desperate, whatever the cost in Syrian lives, to prevent Russian-backed Syrian government forces from driving Washington’s Islamist proxy forces out of Aleppo, the most populous Syrian city before the outbreak of the civil war. Assad’s forces in recent days made a strategic advance in their battle to take control of the besieged city by closing off the last remaining supply route to the “rebel”-held eastern half.

In response to government gains in recent weeks, the US has sharply escalated its lethal attacks on both military and civilian targets. Chris Woods, director of Airwars, told the Guardian, “We tracked a huge increase in civilian deaths [from coalition airstrikes] in Syria in June above May, a rise of 72 percent from the previous month.” Woods says at least 210 civilians have been killed by coalition airstrikes in the battle for Manbij alone.

On Thursday, the leader of the al-Nusra Front, Abu Mohammed al-Jolani, announced that the group was reconstituting itself under the name Levant Conquest Front and severing its formal ties to Al Qaeda. He said the decision, which was praised by the Al Qaeda leadership, was aimed at ending US and Russian bombing of its forces in Syria.

Al-Nusra is the main fighting force opposing Assad and a de facto ally of the United States, although Washington lists it as a terrorist organization and agreed to formally exclude it from a partial ceasefire it reached with Russia last February. In practice, various supposedly “moderate” Islamist groups openly backed by Washington fight alongside al-Nusra against Assad.

Also on Thursday, Russian and Syrian officials announced a plan to allow opposition fighters and civilians in Aleppo safe passage out of the city. They said the plan included an offer of amnesty to insurgents who laid down their arms and food and accommodation to any of the 300,000 civilians trapped in the devastated and food-deprived city who chose to leave.

The United States immediately denounced the plan, with US Ambassador to the United Nations Samantha Power calling it “chilling.” What Washington finds “chilling” is not the prospect of more bloodshed and perhaps thousands dying of starvation and lack of fresh water, but a decisive defeat of its Al Qaeda-linked proxy forces.