External Content

The following content is sourced from external partners. We cannot guarantee that it is suitable for the visually or hearing impaired.

BEIRUT (Reuters) - U.S.-backed militias in Syria have captured an ancient citadel from Islamic State in a strategically significant advance against the jihadist group in its stronghold of Raqqa province, a spokesman said on Friday.

The Jabar citadel on the banks of Lake Assad was captured by the Syrian Democratic Forces (SDF) alliance on Thursday, militia spokesman Talal Silo told Reuters. It is located near a dam on the Euphrates River that the U.S.-backed alliance also aims to capture in the current phase of its campaign.

"The direction of our forces is towards the area of the dam at present," Silo said. SDF advances had been slowed by thick fog that had allowed Islamic State fighters to use infiltration tactics to attack SDF positions, he said. The weather had now improved, he said in an interview over the internet.

The SDF, which includes the powerful Kurdish YPG militia, are just a few kilometres (miles) from the dam. The SDF is the main partner for the United States in the campaign it is leading against Islamic State in Syria.

Islamic State is also being fought in separate campaigns by Turkish-backed Syrian rebels in areas further west and by the Russian-backed Syrian army in Deir al-Zor province and near the city of Palmyra, which IS seized for a second time in December.

The SDF launched a multi-stage operation in Raqqa province in November aimed ultimately at capturing the city from Islamic State. The first phase captured territory to the north of the city and the current phase is targeting areas to the west of it.

(Reporting by Tom Perry; Editing by Tom Heneghan)