BEIRUT (AP) -- U.S-allied forces said Sunday they have captured Syria's largest oil field from the Islamic State group.
The Kurdish-led Syrian Democratic Forces, who are in a race with Russian-backed Syrian troops to seize parts of the oil-rich Deir el-Zour province, said they are in full control of the Al-Omar field.
The SDF has already driven IS from Deir el-Zour's main natural gas field and smaller oil fields. It says government forces are three kilometers (two miles) away from the fields.
The Syrian Observatory for Human Rights says pro-government forces retreated from the area around Al-Omar field after coming under heavy fire from IS militants. Earlier this month, pro-government forces seized the town of Mayadeen, just across the Euphrates River.
IS captured Al-Omar in 2014, when the group swept across large areas in Syria and neighboring Iraq. The field was estimated to produce around 9,000 barrels a day, making it a key source of revenue for the extremists. Its current potential is unknown, following a series of strikes on IS-held oil facilities by the U.S.-led coalition.
Al-Manar TV, operated by Hezbollah, said the fight for Al-Omar was still underway and denied the SDF's claim to have captured it. The Lebanese militant group is fighting alongside Syrian President Bashar Assad's forces.
IS has suffered a series of major setbacks in recent months, including the loss of the Syrian city of Raqqa, once the extremists' self-styled capital, and the Iraqi city of Mosul. Most of the territory the group once held has been seized by an array of Syrian and Iraqi forces.