Officials with U.S.-led coalition forces are investigating accusations by Syrian activists who say airstrikes killed at least 20 civilians in a village near the Islamic State stronghold of Raqqah, a coalition spokesman said Wednesday.
The spokesman, U.S. Col. John Dorrian, said coalition airstrikes occurred near Heisha, but he said he could not address civilian casualties.
"More information is needed to conclusively determine responsibility," said Dorrian, who is based in Baghdad. "We're being very careful and doing the best we can to minimize the impact on innocent civilian life. … We're trying to be very prudent about it."
The Britain-based Syrian Observatory for Human Rights said at least 20 civilians, including nine women and two children, were killed as they sought shelter from warplanes. About 30 people were wounded, the observatory said.
The coalition provides air support in the region for the Kurdish-led Syrian Democratic Forces, which committed 30,000 fighters to an offensive launched Sunday on Raqqah, the extremist group's de facto capital.
Seven coalition airstrikes were conducted in the area Tuesday against a half-dozen Islamic State tactical units, destroying three fighting positions, a vehicle and a car bomb facility, according to a coalition statement.
Dorrian said coalition officials also were investigating allegations that another U.S.-led coalition airstrike killed eight civilians, including three children, in the Iraqi village of Faziliya, north of Mosul, late last month.
Coalition forces have been advising and supporting Iraqi troops who launched a separate offensive against Islamic State in Mosul on Oct. 17.
U.S. officials previously acknowledged that a coalition airstrike against Islamic State in the eastern province of Dair Alzour on Sept. 17 mistakenly hit Syrian government troops, killing 62.
Chris Kozak, a Syria analyst at the Washington, D.C.-based Institute for the Study of War, said that while activist accounts are not always accurate, because it can be difficult to distinguish coalition airstrikes from those by Russian or Syrian government warplanes, "the timing of the airstrike lines up with this new offensive."
"This is something that will likely generate some outcry" but not derail the Raqqah offensive, Kozak said. "Forces on the ground will press forward regardless."
U.S. Central Command announced Wednesday that during the past year, two dozen U.S. airstrikes in Iraq and Syria may have killed 64 civilians.
"We have teams who work full time, to prevent unintended civilian casualties," said Col. John J. Thomas, spokesman for U.S. Central Command. "Sometimes civilians bear the brunt of military action, but we do all we can to minimize those occurrences even at the cost of sometimes missing the chance to strike valid targets in real time."
The list includes numerous airstrikes outside Raqqah and Mosul, but not the most recent ones associated with the offensives.