Originally published at Daily Kos

Less than 10 days after US-led air strikes killed scores of civilians in and around Manbij, Syria, another US strike targeting Islamic State militants in the same area has reportedly killed 28 more civilians.

The UK-based Syrian Observatory for Human Rights reports Thursday’s bombing in al-Ghandour, 23 km (14 miles) from Manbij in Aleppo province, killed 20 men, 7 children and a woman. Thirteen others died in the attack, but their identities have not yet been established.

US Central Command (CENTCOM), which oversees US military operations in the Middle East, said on Thursday that it had “initiated an assessment following internal operational reporting that a strike today near Manbij, Syria may have resulted in civilian casualties.”

The latest deadly attack came one day after the US military announced it was launching a formal investigation of the July 19 bombing of Tokkhar village, where at least 56 civilians were killed. Another 21 civilians were killed in a US-led air strike on Manbij.

“The death toll is 117. We could document 73 civilians including 35 children and 20 women. The rest of the dead bodies are charred, or have been reduced to shreds,” local activist Adnan al-Housen told the Guardian in the wake of the July 19 strikes. SOHR said 44 children, 17 women and 8 prisoners were killed in those attacks. Chris Woods, lead researcher for the UK-based monitoring group Airwars, said as many as 203 civilians may have been killed in the bombings.

However, US Army spokesman Col. Christopher Garver said he believed 10-15 civilians were killed by the allied bombardment.

The swift US admission of civilian casualties in the latest air strike stands in stark contrast to the usual initial denials issued by Pentagon officials, who as late as last December claimed that 20,000 Islamic State fighters and only 6 civilians had been killed by the more than 28,000 bombs dropped in 8,600 aerial attacks in the previous 17 months. A CENTCOM assessment released on Thursday claimed only 14 civilians were killed by US air strikes from July 28, 2015 to April 29, 2016.

Woods praised the US for launching an investigation of the July 19 bombing so soon after the incident occurred.

“This is the fastest admission of likely civilian casualties that we’ve seen from the coalition from the event to a declaration of an investigation. This is a welcome move. If the public accounts are accurate, this is the single worst civilian casualty event of the entire war,” he said, referring only to US-led attacks.

Some leading Republicans have criticized the US military for trying to wage a “zero civilian casualty” campaign in Syria and Iraq.

“If we’re trying to avoid one civilian casualty in not hitting a legitimate target, we’re allowing the Islamic State to continue to commit atrocities and murder against the people on the ground,” Rep. Martha McSally (R-AZ), a retired Air Force squadron commander and A-10 pilot, said last June.

“It’s insane,” Sen. John McCain (R-AZ), chairman of the Armed Services Committee and also a former military pilot, said at the time. “Seventy-five percent of those combat missions return to base without dropping a weapon.”

In the wider US-led war against Islamist terrorism, as many as 1.3 million men, women and children were killed during the conflict’s first decade, according to a 2015 reportpublished by the Nobel Prize-winning International Physicians for the Prevention of Nuclear War, Physicians for Social Responsibility and Physicians for Global Survival.

Some defenders of the US-led bombing campaign note that the number of Syrian civilians killed by coalition air strikes is but a tiny fraction of the 400,000 civilians believed to have perished during the country’s 5-year civil war.

Both Republican presidential nominee Donald Trump and his Democratic rival Hillary Clinton have pledged to continue the war against Islamic State. Trump has said the fight may require additional American “boots on the ground,” while Clinton has also said she would escalate the war, including by establishing a no-fly zone inside Syria that critics assert would risk sparking a wider conflict, possibly with Russia.

Over the past half century, the US military has killed more foreign civilians than any other force on Earth, including more than a million people in Vietnam, Laos and Cambodia in the 1960s and 1970s and hundreds of thousands of Iraqis during the current global anti-terrorism campaign.