The U.S. may have killed civilians in an airstrike meant to hit an Islamic State target in Syria this week, the military said on Wednesday.

U.S. Central Command said reports of civilian casualties caused by a strike Tuesday on an Islamic State weapons facility near Raqqah are "credible." After the weapon was already dropped, a non-military vehicle drove into the target area and those inside the vehicle may have been killed, the statement said.

The finding that the report is credible is just the initial assessment. Next, a joint task force will review the strike to determine whether a full investigation is necessary.

Officials say the U.S. military takes every precaution to avoid civilian casualties, including strict rules of engagement that have drawn criticism.

In July, U.S. Central Command released a report that found six U.S. airstrikes between July 28, 2015, and April 29, 2016, killed 14 civilians.