More than 20 children are thought to have been among at least 56 civilians killed by US-led coalition airstrikes near Manbij
Syrian activists have called for widespread protests after dozens of civilians were reportedly killed in US-led coalition air strikes in what one monitor has called the "worst week" for civilians in the two years since the coalition entered the war.
Children were among at least 56 civilians killed on Tuesday in raids by coalition warplanes. The people were fleeing the village of al-Tukhar near the key Islamic State (IS) stronghold of Manbij, according to the Syrian Observatory for Human Rights.
Facebook pages managed by Syrian activists urged people around the world to take to the streets to protest the deaths under the banner "Manbij is being exterminated".
"We ask all Syrians, whatever their affiliations or sects, and all free people of the world and especially the people of Manbij to stand in solidarity with our devastated city on Sunday, July 24," wrote one page that publishes local news about Manbij.
It said it was calling for demonstrations in reaction to "the massacres carried out by coalition warplanes, with the latest...in al-Tukhar".
The village lies 14km north of Manbij, which has been repeatedly targeted by coalition raids in support of an offensive to wrest the town from IS control.
Activists on the "Manbij News" page called for protests in several Turkish cities including Istanbul and Gaziantep.
Another Manbij-affiliated page posted photographs of demonstrators gathering on Wednesday in the rebel-held town of Azaz, further west, to condemn the raids.
"Our children will tell God everything," read one Arabic-language sign held by a young boy.
"The al-Tukhar massacre is a stain of shame on humanity," another sign said.
Asked about the al-Tukhar raids, the US-led coalition said it had recently "conducted air strikes near Manbij" and was looking into the reports of civilian casualties.
Airwars, a website tracking civilian deaths by the US-led coalition, said in a tweet earlier that this week was the deadliest for civilians since the coalition began operations against IS.
The raids also drew condemnation from the UN's children agency, which said that "more than 20 children were reportedly killed" in the raids on al-Tukhar.
"Such horrific incidents confront parties to this conflict with their shared responsibility to respect international humanitarian laws that protect children in war," said UNICEF's Syria representative, Hanaa Singer.
"No matter where they are in Syria or under whose control they live - absolutely nothing justifies attacks on children."
The Syrian government also condemned the attack in a statement released on Tuesday.
“The government of Syrian Arab Republic condemns, with the strongest terms, the two bloody massacres perpetrated by the French and US warplanes and those affiliated to the so-called international coalition which send their missiles and bombs to the civilians instead of directing them to the terrorist gangs," said the foreign ministry in a statement released on the SANA news agency.
"Syria also affirms that those who want to combat terrorism seriously should coordinate with the Syrian government and army."
More than 100,000 people had been killed in the conflict when the UN stopped its official count in January 2014, saying that it was unable to verify the data it was collecting.
This April, the UN Envoy to Syria Staffan de Mistura estimated that 400,000 people had been killed.