A new analysis of rockets linked to the nerve-agent attack on Damascus, Syria, in August has concluded that the rockets were most likely fired by multiple launchers and had a range of about three kilometers, according to the two authors of the analysis.

The authors said that their findings could help pinpoint accountability for the most lethal chemical warfare attack in decades, but that they also raised questions about the American government’s claims about the locations of launching points, and the technical intelligence behind them.

The new analysis could point to particular Syrian military units involved, or be used by defenders of the Syrian government and those suspicious of the United States’ claims to try to shift blame toward rebels.

The rockets in question were not seen before the Syrian civil war. There is little publicly available information about their internal construction, their manufacturing provenance or their flight characteristics.