BEIRUT (Reuters) - A military alliance fighting together with the Syrian army said it launched an assault in the east of the country on Saturday to drive Islamic State militants from the border with Iraq.

The alliance of Iran-backed Shi’ite militias said the offensive, with Damascus’s military support and Russian air cover, began in the southern corner of Deir al-Zor province.

The attack will target Islamic State all the way up to the town of al-Bukamal, where the Euphrates river meets the Iraqi border, it said.

Iraqi armed forces said on Saturday they had started an offensive to dislodge Islamic State from a border area holding some of the militants’ last towns in the country.