Another source told Sputnik earlier in the day that the explosion near one of the facilities of the Levant Front group in Afrin left six people killed and 10 others injured.
The source noted that the blast followed clashes between two local armed groups.
TSK ve ÖSO kontrolündeki Afrin'de art arda yaşanan 2 patlamada ilk belirlemelere göre 6 kişi öldü, 20 kişi yaralandı. pic.twitter.com/sReug1VE9P— PoLiTiKaLoJi®🇹🇷 (@politikaloji) 27 июня 2018 г.
"The number of victims of two blasts in the city of Afrin reached 11 people, 15 people have been injured," the FSA source said.
Afrin was captured by the Turkish-backed FSA in March as part of Ankara’s offensive against Syrian Kurdish armed groups that were operating in the area.
Damascus expressed its opposition to Ankara’s operating on its territory, saying that Turkey violated Syria’s sovereignty by this move.