( CNN) Two chemical gas assaults have been reported in northern Syria, one in the area where a Russian helicopter was downed a day earlier, killing all five people on board.

In the first alleged assault, cylinders suspected of containing chlorine gas were dropped in residential areas in the towns of Saraqeb in Idlib province, the anti-regime, voluntary search-and-rescue group Idlib Civil Defence said in a post on its Facebook page.

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