The Islamic State is pressing ahead in Anbar Province in western Iraq, seeking to take the town of Amariyat al-Falluja and an important road from the province to Baghdad.
Iraqi forces and police had repulsed an assault last week but another wave began on Wednesday with bombardment from heavy weapons.
The jihadists consolidated their control of another town on the main highway, Hit, defeating the final resistance from a local tribe.
There are also clashes near Lake Tharthar, an important source of irrigation for the area. Iraqi troops were forced to retreat, giving up control of one of the lake’s water-control gates.
The Islamic State and other insurgents took key parts of Anbar at the start of the year, following large protests against the Iraqi Government. Areas seized included the city of Fallujah and parts of the provincial capital of Ramadi.
In contrast to other areas of Iraq, where Iraqi and Kurdish forces — sometimes assisted by US-led airstrikes — have pushed back Islamic State gains, the jihadists have continued to extend their control in western Iraq.
Elsewhere in the country on Friday, the Islamic State is renewing its siege on Mount Sinjar, which came to prominence in August when tens of thousands of refugees — mainly of the Yazidi religious sect — fled there after the jihadists took the town of Sinjar in northwestern Iraq.
And Iraqi soldiers, with US-led air support, are challenging the Islamic State in a counteroffensive north of Baghdad near Baiji.
The Iraqi forces troops are hoping to break the Islamic State’s four-month siege of the Baiji oil refinery. Iraqi officials said their troops had gained control of the western, eastern and southern sides of Baiji city, cutting a key supply route to the jihadists encircling the refinery.
