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'Neurotoxic' attack in Syria

Medecins Sans Frontieres says doctors have treated about 3,600 patients in Syria with 'neurotoxic symptoms' and that 355 of them died. It suggests there are strong indications that chemical weapons have been used.

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Time running out to gather evidence of 'gas attack'

With UN weapons inspectors still refused access into Syria by the Assad regime, it is not yet clear what actually caused so many deaths in Damascus.

Most experts say it looks like some kind of chemical attack took place, but there is disagreement whether a nerve agent like Sarin is to blame.

The chemical evidence will remain for only another 12 to 24 hours, which means time to establish the facts of what happened is running out, as Paul Davies reports.

Warning: This report contains graphic images

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