Claims that at least 30 Syrian civilians were killed on Tuesday when US warplanes hit an ISIS target in Syria have raised concerns that a renewed and aggressive approach to the war on terror may come at an unacceptable human cost.

The US military acknowledged that it had carried out 19 airstrikes in the Raqqa region on Tuesday, but denied knowledge of civilian casualties. This is the second time in one week that the US has been accused by Syria of killing non-combatants.

The Syrian Observatory for Human Rights said on Tuesday that coalition warplanes struck the town of al-Bukamal in the south of the province near the Iraqi border, killing three militants and 13 civilians, and seven civilians in the town of al-Husainiyah.

Last week, the Syrian government claimed that 49 people were killed in American airstrike on Al Jinah, a village in western Aleppo Province. United States officials claimed al-Qaeda were in the building hit by the airstrike, but residents said the warplanes struck a mosque.

President Donald Trump is giving the military more leeway in aggressively fighting terror groups in the region, while also opposing Syrian President Bashar al-Assad. Three weeks ago, Assad used sarin gas in an attack that killed almost 90 Syrians. The US responded with a missile strike targeting the airbase from which the chemical strike originated.Last Thursday, the US dropped its largest non-nuclear bomb on an Islamic State (ISIS) target in Afghanistan.