Sarin was definitely used in Syria's Idlib province in the attack last week, Turkey's health minister is quoted as saying by state-run Anadolu news agency. "In Idlib, the use of sarin gas has become certain," Minister Recep Akdag said, following testing on blood and urine samples of victims of the attack in Khan Sheikhoun, reported the dpa. The results showed traces of sopropyl methyl phosphonic acid, the metabolite of sarin, a banned nerve agent. More than two dozen victims of the attack were brought to Turkey for treatment and three died in a Turkish hospital. Ground samples were also brought across the border from Idlib for testing. Autopsy results were sent last week to The Hague for further testing by the United Nations. Turkey is a staunch supporter of the Syrian opposition and armed groups.