In a crucial strategic advance for the Islamic State (IS), the organization that is tearing Iraq apart, anti-government rebels in Syria who had been loyal to the rival Jabhat al-Nusra switched sides, handing over Al-Omar oilfield, which has the potential to produce up to 75,000 barrels of oil a day.
The development represents a huge step up for the group — formerly known as the Islamic State of Syria & Al-Sham (ISIS) — in its struggle against Al-Nusra, which is backed by Al-Qaeda but regards the new grouping as dangerously extremist.
This means its caliphate now stretches from Deir al-Zour, central Syria, to Abukamel on the Iraqi border. Within neighbouring Iraq, to the east, it holds the cities of Mosul and Tikrit, has free rein in Anbar province and is threatening to attack Baghdad.