France's foreign minister says more signs have emerged of chemical weapons being used in Syria.

France had been looking into reports of that since early this month when the ministry said there were accounts and indicators on the use of chemical weapons in Syria's civil war that needed to be verified.

On Monday, minister Laurent Fabius said outside a meeting of European Union foreign ministers in Brussels that there " are stronger and better substantiated indications of the local use of chemical arms. We have to check this and (we) are doing this with our partners."