Damascus, June 30 : At least 20 Islamic State (IS) militants were killed in a bombing near the Koniko gas field, the largest one in Syria, a UK-based war monitor said on Friday.Planes targeted a convoy of extremists around Koniko, in Deir al-Zour province bordering Iraq, the Syrian Observatory for Human Rights (SOHR) said.Similar bombings were also reported against the cities of al-Mayadin and Deir al-Zour, reports Efe news.