More than two months since U.S.-backed forces launched a major offensive to reclaim ISIS' crown jewel in Syria, thousands of civilians remain trapped in the war-ravaged city of Raqqa. And for those still in the ISIS stronghold, daily life has become a maze of threats and explosions, with few clear indications of what — or who — to avoid in order to stay alive.Civilians in and around the city have been battered — not only by the ISIS militants who block their escape and use them as human shields, but also by airstrikes from those forces seeking to liberate them, according to Amnesty International. In a report released Thursday evening ET, the aid group drew on nearly 100 recent witness interviews to depict the nightmare confronting the up to 25,000 civilians still trapped in the city."Whether you live or die depends on luck because you don't know where the next shell will strike, so you don't know where to run," one witness told the organization.Since June 6, the Syrian Democratic Forces, a mix of Kurdish and Arab troops supported by a U.S.-led coalition, have pushed progressively deeper into the city — and Amnesty International says that as the fight for Raqqa has ramped up, so too has the number of civilians killed accidentally in coalition airstrikes.Over the better part of two months, the group says it has documented the deaths of at least 146 civilians in coalition airstrikes in and around the city — at least 60 of whom are children. The group notes it also knows of at least 30 civilians who have been killed in operations by Russia-backed Syrian government forces farther south.In comparison with some other estimates, Amnesty's numbers are conservative: Airwars, a London-based monitoring group, tells The Washington Post at least 725 civilians have been killed since the offensive began. And an activist-run group, Raqqa is Being Slaughtered Silently, recently said it had documented at least 946, according to Reuters. The British-based Syrian Observatory for Human Rights said coalition airstrikes killed 170 civilians in the span of a week earlier this month.Lt. Gen. Stephen Townsend, the U.S. commander of the operation against ISIS, told reporters earlier this week that it would not be surprising to see increased civilian casualties since the operation's start. But he also expressed some skepticism about how the groups arrived at their estimates."I have seen the reports of increased civilian casualties, and it is probably logical to assume that there have been some increases in civilian casualties because our operations have increased in intensity there," Townsendsaid at a news conference Tuesday in Baghdad."But," he added, "I would ask someone to show me hard information that says that civilian casualties have increased in Raqqa to some significant degree."There is something both military authorities and independent groups can agree on, though: ISIS has centered its strategy on using civilians for cover, exacerbating the violence and making the coalition effort fraught with risk.Amnesty International explains the extremist group's tactics: