Updated June 29, 2017 07:05:41

Photo: Tal Al Jasser (top) was reported to have been killed in an alleged coalition airstrike in Raqqa. (Supplied: Raqqa is Being Slaughtered Silently)

At least 173 civilians have been killed so far this month in the Syrian city of Raqqa, in air and ground operations against the Islamic State group, the UN's top human rights chief says.

United Nations High Commissioner for Human Rights Zeid al-Hussein said the number was a "conservative" figure.

"Civilians must not be sacrificed for the sake of rapid military victories," Mr Zeid said in a statement.

Last month, the UN said coalition airstrikes in Raqqa had lead to a "staggering loss of civilian life" with 300 reported dead from strikes since March.

Meanwhile, monitors said at least 15 civilians had been killed and dozens injured in an air strike on an Islamic State-held held village in eastern Syria.

The DeirEzzor24 website reported that an unidentified jet had dropped cluster bombs on Dablan, about 20 kilometres south-east of the town of Mayadin.

There was no immediate comment from the coalition on Wednesday's reported attack.

Russian and Syrian air forces also carry out airstrikes in the region.

It comes only two days after a US-led coalition strike reportedly killed 42 detainees at an Islamic State prison near Mayadin.

Monitoring groups have sounded the alarm over the civilian death toll in Raqqa as the fight against the Islamic State group heats up.

"It's certainly fair to say that we are seeing numbers of civilians reported killed and numbers of incidents comparable to the worst periods of the Aleppo siege last year when east Aleppo was under bombardment by both Russian and Syrian forces," said Chris Woods, the director of NGO Airwars that monitors airstrikes in Iraq and Syria.

"We are concerned that despite clear evidence from Mosul, that the heavy bombardment of that city led to very heavy civilian casualties, we have not seen in any real change in operational behaviour at Raqqa," he told the ABC.

Photo: The fight for Raqqa began in earnest in early June. (Reuters: Rodi Said)

Topics: unrest-conflict-and-war, syrian-arab-republic

First posted June 29, 2017 06:51:16