Russia has accused Turkey of using three humanitarian organizations to funnel weapons and supplies to IS and other jihadist groups in Syria. Moscow also called for Turkey close the porous border to extremists.

Russia’s UN Ambassador Vitaly Churkin on Friday sent a letter to the UN Security Council saying three Turkish humanitarian organizations were fronts for the country’s intelligence service to send weapons and supplies to extremists in Syria.

“The main supplier of weapons and military equipment to ISIL fighters is Turkey, which is doing so through non-governmental organizations,” Churkin said in a letter dated March 18, referring to the self-declared “Islamic State” (IS) group by another acronym, ISIL.

Read More: Deutsche Welle