MOSCOW, June 30. /TASS/. The Organization for the Prohibition of Chemical Weapons (OPCW) is unaware how sarin was delivered to the Syrian city of Khan Shaykhun, Russian Foreign Minister Sergey Lavrov said on Friday speaking at the Primakov Reading forum.

"Yesterday, on June 29, the OPCW issued a report saying that they are not sure whether sarin that was allegedly found there or had been dropped in bombs from an aircraft," the top diplomat said, citing the organization’s comment on chemical weapons incident in Syria’s Khan Shaykhun on April 4.

"They do not know how sarin was delivered there, can you imagine that? And they have been trying to escalate tensions over the past few months."