Seventeen bodies, including that of a baby, washed up on a beach of Al-Alous on Saturday night, the health aid charity said on social media. Ten more bodies were later found in a different location.
Rescuers fear that the death toll may rise. The search operation continues to find more victims or survivors.
The tragedy casts a spotlight on the perils faced by thousands of migrants attempting to flee war and poverty in the Middle East and Africa. More than 160 migrants drowned in the Mediterranean earlier this week. The UN migrant agency IOM says this year's death toll for the route has passed 1,300.