At least 30 people were killed in Sunday's airstrikes carried out by the US-led international coalition, targeting oil refineries in the northeastern Syrian province of al-Raqqa, the Syrian Observatory for Human Rights (SOHR) said on Monday.
Among the fatalities were members of the Islamic State (IS) terrorist group and workers in the refinery, located in the vicinity of Tel Abiad, a town on the Syrian-Turkish border, Efe news agency reported citing SOHR.
The London-based NGO published on its website alleged footage of the night air raids.
In the video, a coalition aircraft was seen flying over Tel Abiad, followed by a heavy explosion on the ground.
The jihadi organisation in June proclaimed the establishment of a "caliphate" in the territories under its control in Iraq and Syria.
Coalition airstrikes in Syria began on September 23, while operations in Iraq have been intermittent since August.
